Wilderness and Roadless Areas on the Colorado Plateau

Extensive commercial use of the lands of the Colorado Plateau, beginning in the late 1800s and intensifying in the latter part of this century, has resulted in a marked decrease of large, roadless and relatively undisturbed natural areas. Just prior to World War II much of the region, particularly the central Plateau's isolated canyonlands, remained wild or only slightly altered by human activities. Riparian forests of cottonwood and willow shaded the area's streams and rivers, a few large tracts of unlogged forest covered the high plateaus, and many now threatened or endangered species were common. But continued road construction associated with  logging and grazing activities has severely fragmented many of these once expansive areas, allowed invasions by exotic plants and animals, and contributing to forest fragmentation.

Robert Marshall and Althea Dobbins completed a Roadless Areas Inventory for the lower 48 States in 1936. The Colorado River region of southern Utah and far northern Arizona, stretching from the Paria River northeastward all the way to Canyonlands, was at that time the largest contiguous roadless area in the country at nearly 9 million acres. Several other significant roadless areas could be found on the Colorado Plateau at this time as well (Table 1). In just over 50 years most of these natural areas have been dramatically reduced in size or essentially eliminated.

Table 1. Comparison of Roadless Areas of the Colorado Plateau in 1936 and 1992.

On the National Forests of the Colorado Plateau, some United States Forest Service road networks have expanded over twelve-fold since the late 1930s. This great increase in road networks in the last 75 years, due largely to logging activities, has resulted in landscape-wide ecological impacts. These include significant wildlife habitat fragmentation and degradation, formation of routes for the spread of invasive weeds, accelerated erosion rates, and increased stream sediment loads.

Wilderness

The passage of the Wilderness Act by Congress in 1964 called for the protection of certain public lands for their outstanding scenic values. More recently, some already established large wilderness areas have become even more important as centers of biological diversity or as "wilderness recovery areas." Though several wilderness areas exist on National Forest lands of the Colorado Plateau, they comprise just 5% of these forests' total acreage (Table 2).

Table 2. Designated Wilderness on some National Forests of the Colorado Plateau.

The United States Forest Service undertook "Roadless Area Review and Evaluation" (RARE) studies in the 1970s in an attempt to catalogue possible wilderness areas on National Forest lands. The first RARE study was widely criticized for its inadequacy and a second more detailed and comprehensive study, RARE II, was completed in 1979. Even after nearly 100 years of widespread commercial use and extensive road-building in the nation's forests, the study found a few fairly large pockets of undisturbed country still remained. In the Four Corners states over 14 million acres of undeveloped forest lands were catalogued by the agency (Table 3). Today, only a quarter of those remnant lands evaluated in the study have been preserved.

Table 3. USFS RARE II Roadless Areas (1979) and Portion Designated Wilderness

Contribution of Roads to Forest Fragmentation. Increasingly, previously extensive, continuous tracts of forest are being reduced to widely dispersed patches of remnant forest vegetation by logging and road-building, but few measures of the effects of roads on forest fragmentation are available. This study looks at the importance of roads in delineating and quantifying landscape structure, including the proportion of the landscape occupied by edge habitat, and compares the effects of roads and clearcut logging on forest fragmentation. Adapted from a published journal article by Rebecca A. Reed et al.

Bourne, J. 1998. The end of the roads? Wilderness replaced by pavement. Audubon 100: 58-72.

Reed, R. A., Johnson-Barnard, J. and Baker, W. L. 1996. The contribution of roads to forest fragmentation in the Rocky Mountains. Conservation Biology 10: 1098-1106.

U.S. Forest Service. 1979. RARE II: Final Environmental Statement: Roadless Area Review and Evaluation. U.S.D.A., Forest Service, Washington, D.C.