The world’s best record of terrestrial Cretaceous life, Merriam’s life zones, and Colorado River silt
I. Map boundaries: 33 to 40 degrees North; 110 to 114 degrees West
II. Country (State): United States (Arizona, Utah).
III. Overview
This map area includes the western Colorado Plateau, which is marked by dramatic escarpments along all its boundaries, leaving little doubt of its boundaries. To the south, it abruptly drops off at the Mogollon Rim in the Apache and Coconino NFs. To the west, there are the cliffs of the Grand Canyon and Grand Canyon Parashant National Monument. To the north, the Wasatch Plateaus drop off dramatically into the Great Basin. The Grand Staircase-Escalante National Monument is becoming known at the best record of Late Cretaceous terrestrial life. The remains of dinosaurs—hadrosaurs, ceratopsians, and tyrannosaurs—are impressive, with more than 50 genera of dinosaurs represented. There are more than 5,000 square km of fossil-rich Late Cretaceous rocks exposed. The realization of the fossil riches in the area did not come until the 1980s. More than 800 fossil locations are known (Stokstad 2001). In 2011, the sixth entirely new species of dinosaur was discovered in the monument. Fossil of plants and invertebrates are also preserved with the dinosaurs. The monument contains the Wolverine Petrified Forest, the second largest Late Triassic fossil forest known (Ash 2001). Elsewhere in the Colorado Plateau are other notable fossil sites. The Cleveland-Lloyd Dinosaur Quarry is the densest known dinosaur fossil bed from the Jurassic Period, yielding more than 12,000 bones representing 12 dinosaur genera and dinosaur eggs (Hirsch et al 1989). Dinosaur trackways are found in the Grand Staircase-Escalante NM as well as on the Navajo Reservation. Pre-dinosaurian trackways of early four-legged vertebrates, fish fin impressions, and invertebrate impressions are at Glen Canyon National Recreation Area, Capitol Reef National Park, and along the San Rafael Swell (Mickelson, Huntoon, and Kvale 2006). Mammal-like reptiles are found at Comb Ridge and early mammals are found in the Kayenta Formation, both on the Navajo Reservation (Jenkins, Crompton and Downs 1983). The Grand Canyon has Precambrian rocks with fossils of early metazoans (Bloeser et al. 1977).
The Colorado Plateau is a region of natural arches and bridges overlooking canyonlands. The largest of all is Rainbow Bridge, at 290 feet in height and 275 feet. The world’s largest natural bridge spans a side canyon of Glen Canyon on the Colorado River and is a near-perfect parabola. Other notable arches and bridges are in Natural Bridges National Monument to the northeast of Rainbow Bridge, Grand Staircase-Escalante National Monument to the north, the surrounding Glen Canyon National Recreation Area, and the Navajo Nation lands to the south.
There is now only one reservoir in the Colorado Plateau canyonlands along the Colorado River, backed up behind Glen Canyon Dam. There were once plans for more, including two dams in the Grand Canyon, at Bridge Canyon and Marble Canyon, one along the Little Colorado, at Coconino Dam, and one along the Paria River. All were part of a project to bring more water to the lower Colorado River and store it in the dams. The water from other river basins would arrive via an aqueduct from the Columbia basin. The environmental battle over the dams reached its peak in the 1960s. The only feature that was completed was the aqueduct from Lake Havasu to Phoenix and Tucson. One of the criticisms of the dam proposals was that the dams would keep silt from flushing out from the natural scouring that occurs with a free-flowing river (Carter 1966). It was believed that the balance of sand deposition and erosion would be disturbed. This appears to have been a valid criticism, as the Glen Canyon Dam operation has been changed in the last ten years to scour the canyon and restore sand and gravel bars. If water is released only from the Glen Canyon Dam without new sediment input, this is also counterproductive because the water will just wash existing sandbars downstream. What is needed is sediment-laden water. To try to simulate these conditions, water is now released from Glen Canyon after heavy rains flush sediment from the Paria River. Regardless of the success of the new sediment release and scouring strategy, the river will need to be monitored and managed to ensure that rare snails and fish, as well as other native species, are protected by the new river management strategy (Pennisi 2004).
At the San Francisco Peaks in the Kachina Peaks Wilderness, the Colorado Plateau includes a group of volcanoes that last erupted more than 10,000 years ago but overlie large magma chambers (Kerr 1983). In fact, Sunset Crater Volcano NM and Strawberry Crater Wilderness erupted more recently. Thus these volcanoes are potentially dangerous even though they have been quiet in recent years. It was from a basecamp on the slopes of the San Francisco Peaks that C. Hart Merriam developed his theory of life zones in the late 1800s, and this is the precursor to the ecosystem delineation of the world that is the subject of this blog. In the vicinity of the San Francisco Peaks, it is possible to go from desert to alpine tundra in a short distance around Flagstaff and the Grand Canyon. Merriam saw in the San Francisco Peaks a microcosm of the entire United States. The north-south distribution of plants and animals was replicated by the vertical zones on the mountains. He believed that temperature was the key to the observed distribution of plants and animals, and that migration of plants and animals in response to changing climates led to many northern species finding a place to live on higher mountains. The existence of a boreal zone was support for this interpretation. While modern interpretations indicate that things are more complex due to sun angles and other factors, and that zones are not as sharp as envisioned by Merriam, the basic idea that patterns of plants and animals characterize certain ecosystems holds sway today (Maienschein 1994)
On the southern portions of the Arizona Mountains, as the Colorado Plateau drops off to the Sonoran Desert, a transitional vegetation of chaparral appears in the Prescott and Tonto National Forests. This vegetation is similar in appearance to the Mediterranean-climate chaparral in California. However, here it grows in an area where there are summer rains. Like in California, this vegetation is fire-adapted (Mohlenbrock 1986).
IV. Terrestrial Ecoregions
Ecoregions of the Neararctic Biome
Temperate Coniferous Forests
NA 503, Arizona Mountains forests. Ponderosa pine forests predominate in open park-like areas. Above 2,000 m are Douglas-fir and spruce. Found in Arizona on this map; also extends into New Mexico.
Deserts & Xeric Shrublands
NA 1304, Colorado Plateau shrublands. Characterized by extensive and sparse pinyon pine and juniper woodlands. Lower elevations have arid grasslands and sagebrush. Found in Arizona and Utah on this map; also extends into Colorado and New Mexico.
V. Freshwater Ecoregions
Xeric Freshwaters and Closed Basins
129 Vegas-Virgin. This includes the watersheds of the Meadow Valley Wash, Pahranagat Wash, Virgin River, and White River, all in the Las Vegas area and northward in Arizona, Nevada and Utah. Endemic species are three species of spinedace, Virgin River chub, and Moapa speckled dace.
130 Colorado. The portions of this large ecoregion included in this discussion are the Colorado upstream from Lake Havasu including the major tributaries of the Virgin in the Mojave Desert and the Little Colorado, San Juan, and Green in the Colorado Plateau. Endemic fish are humpback chub, bonytail, and razorback sucker, and near-endemics are Colorado spine dace, Colorado pikeminnow, several suckers, and Apache trout.
131 Gila. The portions of this ecoregion included in this discussion include the drainage from the Mogollon Rim in the Arizona Mountain forests and the upper Verde River watershed east of the Juniper Mountains of Arizona. Endemic species are the Santa Cruz pupfish, Gila chub, spikedace, Gila trout, and loach minnow.
VI. World Heritage Site
Grand Canyon National Park, Arizona (location 1 on map). The most spectacular gorge in the world, with two billion years of strata and seven life zones. The park includes the north bank of the Colorado River from Pearce Ferry on Lake Mead to Navajo Bridge, and the south bank from the Hualapai Reservation to the Navajo Reservation. The lower elevations of the park are in the Mojave Desert, the middle-elevations are in the Colorado Plateau, and the high elevations, including the visitor areas at the North Rim and South Rim, are in the Arizona Mountains forests. The North Rim includes the Bright Angel Point area, Point Imperial, Point Sublime, Swamp Point, Toroweap Overlook, and and Cape Royal Overlook areas. The South Rim includes the Grand Canyon Village, Hermits Rest, and Desert View areas. Lipan and Yaki Points along the South Rim are an IBA for raptor migration, with 10,000 birds spotted during fall migration season at each location. Colorado River areas included in the park are Lower Granite Gorge, Middle Granite Gorge, Granite Gorge, and Marble Canyon. Marble Canyon is considered an IBA for California condor and waterfowl migrants. Terrestrial ecoregions NA503, NA1308, and NA1304.
VII. Man and the Biosphere Reserves
Beaver Creek Experimental Watershed, Coconino National Forest, Arizona (location 2 on map)). Watershed management research from the 1950s occurred in a pinyon-juniper and ponderosa pine forest. This is a 250,000-acre research site to determine how much water yield can be increased by altering vegetation. The biosphere reserve includes the watershed from Camp Verde upstream and today includes Montezuma Castle National Monument, Munds Mountain Wilderness, and Wet Beaver Wilderness in addition to other Coconino National Forest lands. Ecoregion NA503.
VIII. National Forest (NF) System
Ashley NF, Utah (location 3 on map). The unit of the forest shown in this map area rises sharply above the Bad Land Cliffs and Nine Mile Canyon. Ecoregion NA530 and NA1304.
Beaver Creek Experimental Watershed, Coconino National Forest, Arizona. See description under Biosphere Reserves.
Coconino NF, Arizona (2). The forest includes the red rock formations of Sedona and Oak Creek Canyon and the San Francisco Peaks north of Flagstaff (see description of San Francisco Peaks in the overview paragraphs). In addition to the San Francisco Peaks, the forest has another special treasure, Sedona and the Oak Creek Canyon. The red rock formations (otherwise known as new age energy vortices) of Sedona are mostly on national forest lands. The forest includes the West Clear Creek, Fossil Springs, Kachina Peaks, Kendrick Mountain, Munds Mountain, Red Rock-Secret Mountain, Strawberry Crater, Sycamore Canyon, Wet Beaver Wilderness areas, as well as a long section of the Arizona National Scenic Trail. The Beaver Creek Experimental Watershed is described under Biosphere Reserves. A chain of lakes southeast of Flatstaff which starts at Lower Lake Mary and extends for 25 miles through Mormon Lake to Hay Lake in the southeast is the Anderson Mesa IBA. Anderson Mesa with its lakes and wetlands is an IBA for ducks and spring migrants. North-flowing canyons from the Mogollon Rim in the Coconino east of Baker Butte are part of the Mogollon Rim Snowmelt Draws, an IBA for breeding warblers. Lower Oak Creek between Red Rock State Park and Page Springs state fish hatchery supports a mature riparian gallery forest and is an IBA. Near Flagstaff is the Arboretum at Flagstaff, located on 200 acres of Coconino NF lands in a ponderosa pine forest. Ecoregions NA503 and NA1304.
Dixie NF, Utah (4). The westernmost area, bordering Nevada, contains the Pine Valley Mountains, which rise sharply from the desert floor. The Markagunt Plateau unit features Navajo Lake, which was dammed by a lava flow. Water drains out of the lake on a red limestone cliff, forming a waterfall. The 11,000-foot western edge of the plateau is called Bryan Head Peak. The unit to the east features Red Canyon, while further to the east is Hell’s Backbone and the Aquarius Plateau. Wilderness areas include Ashdown Gorge, Box-Death Hollow, Cottonwood Forest, Pine Valley Mountain, Ecoregions NA530, NA1304, NA1305.
Fishlake NF, Utah (5). At Fish Lake in the eastern unit, the outline on the map suggests a fish. The lake was dammed by a glacier and is lined with aspens. The area to the south of Fish Lake is the largest contiguous tract of sagebrush in Utah and is an IBA for the greater sage grouse. In the western unit is the Tushar Range, a high-altitude area where eight peaks exceed 10,000 feet in elevation. Ecoregions NA530, NA1304, NA1305.
Fort Valley Experimental Forest, Coconino NF, Arizona (6). This first experimental forest in the nation began with studies on ponderosa pine regeneration. There are three units north of Flagstaff and two units south. Ecoregion NA503.
Kaibab NF, Arizona (7). The three units include the high elevation Kaibab Plateau north of the Grand Canyon, home of the rare Kaibab squirrel and a National Natural Landmark, a second area of pinyon-juniper south of the Grand Canyon, and a third area west of Flagstaff which includes Sycamore Canyon wilderness. Wilderness areas are Kanab Creek, Kendrick Mountain, Saddle Mountain, and Sycamore Canyon. Ecoregions NA503, NA1304.
Long Valley Experimental Forest, Coconino NF, Arizona (8). This area 46 miles south of Flagstaff is the last unharvested ponderosa pine forest in the U.S. The focus here is on ponderosa pine regeneration in a limestone-sandstone soil and the ecological restoration process. Ecoregion NA503.
Manti-LaSal NF, Utah (9). Skyline Drive follows the high, cool Uinta Mountain range for more than 70 miles. The Grove of the Giant Aspens, with trunk diameters up to 38 inches, is also found here. Wilderness areas include Dark Canyon. Ecoregions NA530, NA1304, NA1305.
Prescott NF, Arizona (10). In the high desert are flowering yuccas, agaves, and cacti, whereas at higher elevations pinyon-juniper and oak grow. Included in the forest are Apache Creek, Castle Creek, Cedar Bench, Granite Mountain, Juniper Mesa, Pine Mountain, Sycamore Canyon, and Woodchute Wildernesses. Ecoregion NA503.
Sierra Ancha Experimental Forest, Tonto NF, Arizona (11). This is a watershed studies area in a chaparral shrub and conifer forest. Ecoregion NA503.
Sitgreaves NF, Arizona (12). Along the Mogollon Rim, a continuous vertical cliff 1,000 feet high, the Sitgreaves is a vast ponderosa pine forest. North-flowing canyons from the Mogollon Rim in the Sitgreaves are part of the Mogollon Rim Snowmelt Draws, an IBA for breeding warblers. Also located in the map area is Chevelon Canyon, draining north to the Little Colorado River. North of Show Low is Pintail Lake, a created wastewater treatment wetland that attracts waterfowl and has become a stop to view wetland and water birds. Ecoregions NA503 and NA1304.
Tonto NF, Arizona (13). The southern parts, such as the Superstitition Wilderness, are in the Sonoran Desert, with saguaros, cholla, and cacti, while in the north this grades to a ponderosa pine forest. Diamond Point is a mountain with an abundance of quartz crystals. The Mazatzal, Sierra Ancha, and Superstition wilderness areas are in the forest, as is a long section of the Arizona National Scenic Trail. Ecoregions NA503 and NA1310.
IX. National Landscape Conservation System (wilderness areas are in a separate list below)
Agua Fria National Monument, Arizona (location 14 on map). This 2,000-foot deep canyon is in an area of grasslands 40 miles to the north of Phoenix. A river trail provides access to a riparian area and scenic views. The riparian corridors provide breeding habitat for 28 birds of special conservation status and are considered an IBA. Ecoregion NA503.
Grand Canyon-Parashant National Monument, Arizona (15). The monument includes overlooks of the western Grand Canyon managed by the National Park Service, including Kelly Point, Twin Point, and Whitman Canyon. The BLM portions of the monument include Grand Wash Cliffs Wilderness, Mount Trumbull Wilderness, Mount Logan Wilderness, and part of Paiute Wilderness. The BLM portion also includes canyons, mountains, and buttes of the Shivwits Plateau and Grand Wash Cliffs, the latter of which is the boundary between the Mojave Desert and the Colorado Plateau. Ecoregions NA1304 and NA1308.
Grand Staircase-Escalante National Monument, Utah (16). Known as a treasure trove of dinosaurs (see narrative above), the park offers scenic drives, slot canyons, hoodoos, dinosaur tracks, and arches. The three major sections, from west to east, are the Grand Staircase, Kaiparowits Plateau, and the Escalante River canyons. This is one of the most remote areas in the lower 48 states. Ecoregion NA1304.
Red Cliffs National Conservation Area, BLM St. George Field Office, Utah (17). Just to the south of the Pine Valley Mountains of the Dixie NF, this area includes the Cottonwood Canyon and Red Mountain wilderness areas. It is meeting place of three ecoregions (Colorado Plateau, Great Basin, and Mojave Desert) and protects the desert tortoise. Populations here are the densest in its range. Adjacent is Snow Canyon State Park. Ecoregions NA 1304 and 1308.
Vermillion Cliffs National Monument, BLM Kanab Field Office, Arizona (18). Considered one of the best canyon backpacking areas in the world, the site is known for slot canyons, arches, and hanging gardens of ferns. Vermillion Cliffs are 3,000 feet in height. Part of the Paria Canyon-Vermillion Cliffs Wilderness is included in the monument, as well as the Paria Plateau, which is not designated as wilderness. Ecoregion NA1304.
X. National Natural Landmarks (NNLs)
Barringer Meteor Crater, Meteor Crater Enterprises, Inc., Arizona (location 19 on map). This one-mile diameter, 550-foot deep impact structure is evidence of an event that took place 50,000 years ago. A meteor with a diameter of 150 feet and a speed of 35,000 miles per hour struck this spot, vaporizing rock and throwing chunks for 24 miles. It is one of the best preserved impact sites. Ecoregion NA1304.
Cleveland-Lloyd Dinosaur Quarry, BLM Price Field Office, Utah (20). The densest known dinosaur bed from the Jurassic Period, the site has yielded 12,000 bones from seven genera, and several thousand more are yet to be excavated. The site was apparently some kind of predator trap, since 66 percent are from the meat-eating genus Allosaurus. The bones have been distributed to 65 museums around the world. A visitor center is on site. Ecoregion NA1304.
Comb Ridge, Monument Valley Tribal Park, Navajo Nation (21). Mammal-like reptile fossils of a rodent-like organism are found north of Kayenta; they lived from the late Triassic to mid-Cretaceous periods (200 to 175 million years ago). Comb Ridge is the only location where these fossils are found in North America. The similarity to other fossils in South Africa and South America provides support for continental drift. Other herbivorous dinosaurs have been found north of the San Juan River along Comb Ridge in Utah (Sertich and Loewen 2010). Ecoregion NA1304.
Kaibab Squirrel Area, Grand Canyon National Park and Kaibab National Forest, Arizona (7). The Kaibab squirrel is a species that is only found on the North Rim of the Grand Canyon National Park and the Kaibab Plateau within Kaibab NF. The elevation range of the ponderosa pine forests where they are found is about 5,500 to 8,000 feet in this area. The squirrels found south of the Grand Canyon are Abert squirrels. It is often used in biology textbooks as an example of evolution when a species becomes isolated. Ecoregion NA503.
Little Rockies, BLM Henry Mountains Field Station, Utah (22). This is the classic geologic site for igneous intrusive sills, plugs, and dikes into sedimentary structures. The two main mountain peaks are Mount Ellsworth and Mount Holmes, both to the east of Route 276 and to the west of Hite in the Glen Canyon NRA. Ecoregion NA1304.
XI. National Park (NP) System
Bryce Canyon NP, Utah (location 23 on map) Known for its famous spires, or hoodoos, which are erosional features below the rim of the Paunsaugant Plateau, the park spans 2,000 feet in elevation. Forests and meadows are on top of the 9,000-foot plateau. An extensive scenic trail network winds among the hoodoos from Fairyland Point south to Rainbow Point, while a road follows the rim 18 miles between the two points. Ecoregion NA1304.
Canyonlands NP, Utah (24). A land of canyons, mesas, river gorges, and buttes overlooks the canyons of the Green and Colorado Rivers. Only the western portion of the park (the Maze) is on the map area. The Maze overlook and the Land of Standing Rocks are accessible by primitive roads from the west. The Upheaval Dome structure is an impact crater 10 km in diameter that was formed 170 million years ago. The Horseshoe Canyon Unit is an isolated unit separated from the rest of the park known for rock art. The 52-mile Stillwater Canyon along the Green River in the park is used for float trips. Ecoregion NA1304.
Capitol Reef NP, Utah (25). Waterpocket Fold, a 100-mile-long monocline, is protected in this park, which extends from the high Wasatch Plateaus to the Colorado River. The west side of the fold is 7,000 feet higher than the east side. The Burr Trail Road ascends the southern part of the fold in a series of switchbacks. Rock art panels can be seen on canyon walls. The Fremont River provides riparian areas and is a migration corridor, making it an IBA. North of the fold is Cathedral Valley, which contains free-standing monoliths, the Gypsum Sinkhole, and Glass Mountain. Fossil stromatolites are found in the sandstones of the park. Trackways left by early Triassic fish, reptiles, and amphibians are found in the park. Ecoregion NA1304.
Glen Canyon National Recreation Area, Arizona and Utah (26). In addition to Lake Powell, this area includes the right bank of the Colorado River from the Navajo Bridge upstream to the San Juan River, and the right bank of the San Juan River from the Colorado upstream to Goosenecks. Lee’s Ferry, Wahweap, Bullfrog, Hite, and Halls Crossing are major visitor areas. In addition, the Escalante River and its canyons, the Dirty Devil River canyons, Cataract Canyon, and the Orange Cliffs overlooking the Green River are included in the park area. Ecoregion NA1304.
Grand Canyon NP, Arizona (1). See description under world heritage sites.
Montezuma Castle National Monument, Arizona (2). This two-unit area includes cliff dwellings and Montezuma Well, both along Beaver Creek in the Coconino NF. The unique aquatic habitat found in Montezuma Well, a collapsed limestone sinkhole, harbors an endemic leech species which feeds on an endemic amphipod (Govedich and Bain 2005). Ecoregion NA503.
Natural Bridges National Monument, Utah (27). This area preserves three natural bridges at the head of White Canyon east of the Colorado River. From north to south, these are Sipapu Bridge, Kachina Bridge, and Owachomo Bridge. Ecoregion NA1304.
Navajo National Monument, Navajo Nation (28). This cultural site preserves cliff dwellings. Ecoregion NA1304.
Pipe Spring National Monument, Arizona (29). This preserves a desert oasis used by the Kaibab-Paiute Nation and Mormon settlers.
Rainbow Bridge National Monument, Utah (30). The world’s largest natural bridge, 290 feet in height, is accessible from Lake Powell via a boat trip of 50 miles from Wahweap Marina to the west or 50 miles from Bullfrog or Halls Crossing Marinas to the north. See Overview text. Ecoregion NA1304.
Sunset Crater Volcano National Monument, Arizona (31). Between 1040 and 1100 CE, this cinder cone formed on the eastern edge of San Francisco Peak and continued erupting up until 1250 CE. It is one of 600 known volcanoes in northern Arizona. Ecoregion NA503
Tonto National Monument, Arizona (11). This national park system unit surrounded by the Tonto NF preserves cliff dwellings. Ecoregion NA503.
Tuzigoot National Monument, Arizona (32). This preserves a hilltop pueblo overlooking the Verde River near Clarkdale. The Verde River both upstream and downstream of the park, Peck’s Lake, and Tavasci Marsh in the vicinity of Clarkdale and Cottonwood is an IBA for marsh birds and waterfowl. Ecoregion NA503.
Walnut Canyon National Monument, Arizona (33). Just east of Flagstaff are 700-year-old cliff dwellings. Six miles of the 20-mile long canyon are in the national monument; the rest is in Coconino NF. NA503.
Wupatki National Monument, Arizona (34). This site preserves pueblos at the edge of the Colorado Plateau. NA1304.
Zion NP, Utah (35). The tallest sandstone escarpments in the world rise 2,000 feet above the valley of the Virgin River. Major visitor areas are Kolob Canyon, which includes a trail to Kolob Arch, one of the world;s largest freestanding arches, the Kolob Terrace Road, and Zion Canyon with Emerald Pools, Weeping Rock, and the Narrows. The park is an IBA for breeding Mexican spotted owls, California condor, and peregrine falcon. Wild and Scenic Rivers included in the park are listed in the WSR section. Ecoregion NA 1304.
XII. Federal Recreation Lakes
Bartlett Dam and Reservoir, Bureau of Reclamation, Arizona (location 36 on map). Located on the Verde River in the Tonto National Forest, the reservoir is just north of the Phoenix metropolitan area. Ecoregion NA503.
Glen Canyon Dam and Lake Powell, Bureau of Reclamation, Arizona-Utah (26). See Glen Canyon National Recreation Area in National Park system.
Horse Mesa Dam and Apache Lake, Bureau of Reclamation, Arizona (13). This dam and reservoir is located on the Salt River in the Tonto National Forest 65 miles east of Phoenix. The Four Peaks Wilderness is on the north shore. Ecoregion NA503.
Horseshoe Dam and Reservoir, Bureau of Reclamation, Arizona (37). Located on the Verde River in the Tonto National Forest, the reservoir upstream of Barlett Reservoir in the Phoenix metropolitan area. Ecoregion NA503.
Huntington North Dam, Bureau of Reclamation, Utah (38). This 240-acre irrigation lake on Huntington Creek is in the San Rafael watershed of the Colorado Plateau. Huntington State Park provides recreation facilities. Ecoregion NA1304.
Theodore Roosevelt Dam and Reservoir, Arizona (11). This dam in the Tonto National Forest 85 miles east of Phoenix creates a 17,000-acre reservoir when full. Ecoregion NA503.
XIII. National Trail System
Arizona National Scenic Trail (NST), Arizona. Extending 800 miles from Mexico to Utah, the trail crosses the Vermillion Cliffs NM, Kaibab NF, Grand Canyon NP, Coconino NF, Tonto NF, Four Peaks Wilderness, Superstition Wilderness, Coronado NF, Oracle State Park, Saguaro NP, and Coronado National Memorial. Ecoregions NA302, 503, 1303, 1304, 1310.
Aspen Spring National Recreation Trail (NRT), Hualapai Mountain Park, Mohave County, Arizona (location 39 on map). This ten-mile trail offers spectacular views and winds among an aspen forest, at an elevation range from 6,200 to 8,200 feet. Ecoregion NA1304 and 1305.
Benham NRT, Kaibab NF, Arizona (40). This four-mile trail begins south of Williams on county road 73 and reaches the summit of 9,000-foot Bill Williams Mountain. Ecoregion NA503.
Bill Williams Mountain NRT, Kaibab NF, Arizona (40). This four-mile trail begins in Williams at exit 161 on I-40 and reaches the summit of Bill Williams Mountain. Ecoregion NA503.
Black Canyon NRT, BLM Phoenix District, Arizona (14). This 80-mile trail from State Route 74 west of New River to the Prescott NF east of Mayer follows a route historically used for sheep herding. Ecoregions NA503 and NA1310.
Bright Angel NRT, Grand Canyon NP, Arizona (1). From the trailhead at Kolb Studio in Grand Canyon Village, this trail descends eight miles to the Colorado River. Ecoregion NA1304.
General George Crook NRT, Coconino and Sitgreaves NFs, Arizona (41). This is a 138-mile historic wagon road along the Mogollon Rim, from State Route 260 east of Camp Verde to the Rim Visitor Center on State Route 260 near Fort Apache. Spectacular views from the top of the 400-foot rim are offered. Ecoregion NA503.
Gooseberry Mesa NRT, BLM St. George Field Office, Utah (42). This is an 18-mile series of mountain biking trails to the southeast of Hurricane. Ecoregion NA1304.
Granite Mountain NRT, Granite Mountain Wilderness, Prescott NF, Arizona (43). This four-mile trail begins at Granite Basin Lake and climbs to the top of the 7,200-foot mountain, beginning in chaparral and ending in a ponderosa pine forest with a view of Prescott and the Bradshaw Mountains. Ecoregion NA 503
Highline NRT, Tonto NF, Arizona (41). This 50-mile trail has a western trailhead at State Route 87 and an eastern trailhead at State Route 260. It is known for views and rock formations at the foot of the Mogollon Rim. Part of the trail is used by the Arizona NST. Ecoregion NA503.
North Kaibab NRT, Grand Canyon NP, Arizona (1). From the trailhead at Bright Angel Point on the North Rim, this trail descends 14 miles to the Colorado River. Ecoregion NA503 and NA1304.
Parks NRT, Kaibab NF, Arizona (40). This one-half mile trail is located at the Parks Rest Area on I-40 ten miles west of Flagstaff. Ecoregion NA503.
Prescott Peavine NRT, City of Prescott, Arizona (43). This 5.5-mile rail-trail passes Granite Dells and Watson Lake north of Prescott. Watson and Willow Lakes, city watershed lakes accessible from the city’s trail system, are an IBA for waterfowl migration. Ecoregion NA503.
River NRT, Grand Canyon NP, Arizona (1). This two-mile trail in the bottom of the Grand Canyon connects the Bright Angel Trail with the cross-canyon North and South Kaibab Trails.
Sixshooter Canyon NRT, Tonto NF, Arizona (44). From the Icehouse CCC Campsite south of Globe, this trail ascends six miles to Pinal Peak in a ponderosa pine forest. Ecoregion NA503 and NA1303.
South Kaibab NRT, Grand Canyon NP, Arizona (1). This trail descends seven miles to the Colorado River from Yaki Point on the South Rim. Ecoregion NA1304.
Wilson Mountain NRT, Redrock-Secret Mountain Wilderness, Coconino NF, Arizona (45). Just to the north of Sedona is this five-mile trail at the south entrance to Oak Creek Canyon. The trail climbs 2,300 feet and offers views of Oak Creek Canyon, Sedona, Coffee Pot Rock, Capitol Butte, Sterling Canyon and the Verde Valley. Ecoregion NA503.
CONTINUED NEXT MONTH—National Wild and Scenic River System, National Wilderness Areas, state, local, and private sites in Colorado Plateau and Arizona Mountains west of 110th meridian
