Its geography punctuates the horizon — one of the largest free-standing mountains in the country — as the Rio San Antonio in northern New Mexico flows from its headwaters along the continental divide and tumbles through aspen forests, sub-alpine parks, and stands of mixed conifer before snaking east through sagebrush plains towards San Antonio Mountain. Along the flanks of this peak, the river flows through a rugged canyon and merges with the Rio de Los Pinos just across the Colorado border
This remote and harsh landscape holds many treasures. It harbors three native fish species: the Rio Grande Chub, Rio Grande Sucker, and Rio Grande Cutthroat Trout. Seasonal waterfowl, a large elk population, and a unique high-country herd of pronghorn are some of its natural riches. San Antonio Mountain is significant to many tribes and pueblos, as its unique dacite basalt has been used for tool making for over 5,000 years.

In the 1800s, a mining boom dramatically increased the human footprint in this watershed. Eventually two million sheep grazed the landscape, and several million board-feet of timber were harvested. Those industries are long gone, but a network of roads, bare soils, and abandoned mills remained. Conditions in the Rio San Antonio watershed reflect this land use history. Still, somehow native fish persisted.

Recently, Trout Unlimited began investigating Cutthroat Trout distribution, habitat conditions, and the potential for native fish to persist in the San Antonio in the face of climate change. In 2021, TU identified a previously unknown population of Rio Grande Cutthroat Trout in the upper reaches of the San Antonio, a population that has survived against all odds. While their resiliency is nothing short of remarkable, their presence on this landscape may be lost if we do not act quickly to restore this vital and vulnerable watershed.

TU has launched a watershed-scale restoration project in the upper Rio San Antonio, where seven miles of in-stream habitat will be repaired over the next seven years. The initial phase begins in fall of 2023 with the restoration of approximately one mile of river downstream from the confluence of the Rio San Antonio and Lagunitas Creek. The work will provide cold-water refuge habitat, increase stream shading, increase flow, and reconnect and rewet adjacent wetlands.

Thanks to funding and support from the National Fish and Wildlife Foundation, Enchanted Circle Chapter of Trout Unlimited, New Mexico Department of Game and Fish, Carson National Forest, and local grazing permittees, TU staff are now leading major restoration efforts in the Rio San Antonio basin. This type of restoration work in northern New Mexico will benefit from a historic, multi-million dollar national agreement with TU and the U.S. Forest Service to improve and restore fish passage, habitat, and water quality for cold-water fisheries and their watersheds across the nation.

By restoring the headwaters of the Rio San Antonio, TU and its partners can provide long-term resilience for Rio Grande cutthroat trout and other native fish by addressing impairments to watershed conditions, instream habitat, and water temperature. By providing colder, cleaner water at the time it’s needed most, these benefits extend to downstream water users, giving our communities and our fish and wildlife a fighting chance in the harder, hotter years to come.