Volume 9, Number 4 Winter 1998

The Rio Grande

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by Mike Cassell, Bureau of Land Management, Alamosa


The Rio Grande River corridor has been used as a migratory route and has provided critical habitat for many species of wildlife for countless millennia. This large river system has also been a travel corridor for humans for 10,000 to 12,000 years. Native Americans traversed the river corridor on hunting expeditions into the valley from their homelands to the south. Beginning in the mid 1700s the Rio corridor was the route used by the Spanish as they settled the northern territory.

Along with the settlers came horses, sheep, goats, and cattle, thus establishing grazing as a permanent use on the landscape. The riparian area along the river has been the most heavily impacted by this grazing activity. In northern New Mexico and into Colorado, the vertical walls of the Rio Grande Gorge provide nesting sites for several raptor species, and render the riparian area virtually inaccessible to livestock. The riparian vegetation through this spectacular area is in a healthy late-seral condition, providing good habitat for wildlife. Up-stream to the north of the gorge the riparian area widens along sweeping meanders in the river, and the land opens into rolling cold desert terrain. The riparian areas have been grazed by livestock for 150 to 200 years. The effects of this activity include the removal of woody species, and maintenance of the riparian community in a early-seral stage consisting of a well cropped, weedy grass and forb community with few woody plants and wildlife habitat in poor condition.

This condition has persisted long enough that residents of the surrounding area do not remember seeing willows or cottonwoods along the river in their or their parents’ lifetimes. Looking at the area, this is easy to believe, until one sees a small piece of the riparian area that the BLM had fenced to exclude livestock in 1983 (see photo). Inside the one-acre fence are hundreds of two- to three- meter tall willows (Salix exiguaSalix amygdaloides) and several young cottonwoods (Populus angustifolia), which demonstrates the potential of this area when grazing is controlled. Thus, the problem lies in controlling season-long grazing.

Much of the east side of the river from State Highway 142 south to the beginning of the gorge is a privately-owned, sparsely-populated subdivision grazed by large numbers of cattle throughout the growing season. On the west side of the river the BLM manages 22 miles of public land, including 12 grazing allotments. The river is the primary source of water for livestock on both banks. In this desert country, cattle are attracted to the succulent vegetation of the riparian area, where they remain until moved or the forage is used up.

On the BLM lands, livestock access to the river is restricted by a fence between the riparian area and the uplands. Small fenced water gaps allow livestock access to the river to drink. These water gaps are temporary due to the fluctuations in the water levels in the river. Until recently the animals on the east side had free access to the river, which they easily crossed; their grazing kept riparian vegetation in an early-seral condition on both sides of the river. The BLM has attempted to remedy this situation by working with the livestock operators in the area. Where this approach has not worked, the BLM has used legal means including impoundment of livestock as a last resort to control the situation. Knowing that this is a temporary solution, the BLM realizes that community involvement is the best way to solve the problems in the corridor. BLM has formed partnerships with Costilla County and the Colorado Division of Wildlife to build a fence on county property on the east side of the river.

Currently about 6 miles of the corridor below State Highway 142 are fenced with another 2 miles left to go to reach the gorge. The fence restricts livestock access to the riparian and river except for two small access points (temporary) which allow cattle down to the river to drink. This fence has had a positive effect on riparian vegetation.

Willows, sedges and rushes are increasing in size and number, as are other species associated with a healthy riparian community. The BLM is also working with The Rio Grande Corridor Advisory Committee (an organization made up of local farmers, ranchers, land owners, environmentalists and government agencies) to bring the riparian back to a healthy sustainable condition. The committee is focusing its attention on the section of the river from the village of La Sauses south to the beginning of the gorge. The committee submitted a proposal to North American Wetlands Conservation Act (NAWCA) requesting funding for projects to benefit the riparian in the corridor. The BLM has just completed the Rio Grande Corridor Plan, an interstate venture with New Mexico, which details management of the corridor for the next 15 years. The main emphasis of the plan in Colorado is restoration of the riparian area to Proper Functioning Condition within the life of the plan.

Projects planned for the corridor include

  • Installation of permanent water gaps for both sides of the river.
  • Completion of the fencing on the east side.
  • Elimination of grazing in the riparian areas on the BLM land until Proper Functioning Condition is attained.
  • The Natural Applied Resource Science Center is planning a study on several aspects of the river beginning next year.
  • A baseline inventory of wildlife.
  • Willow and cottonwood plantings will begin in 1999.

The Rio Grande, in this area, is on its way back to a functional healthy river system. There is a long way to go and many obstacles to overcome. With the support of dedicated individuals and groups working together toward this common goal, there is little doubt that the river will once again provide quality habitat for wildlife as well as a place for people to use and enjoy.