A HIGH-MOUNTAIN HAVEN FOR RIO GRANDE CUTTHROAT TROUT
High in Colorado’s South San Juan Mountains, Western Rivers Conservancy has the rare opportunity to conserve a key inholding in the Rio Grande National Forest. In January 2025, we purchased an 800-acre property with the goal of permanently protecting Cliff Lake, the scenic alpine source of a stream called Castleman Gulch, a headwater tributary to the Alamosa River.
Cliff Lake supports a healthy population of native Rio Grande cutthroat trout, an imperiled and iconic native species in southern Colorado. The lake’s depth of about 20 feet prevents thick ice from accumulating and mitigates winter kill even at its high altitude, allowing it to remain a haven for this isolated population of Rio Grande cutthroat trout. Cliff Lake also provides much-needed clean water to the Alamosa River. A legacy of mining and mineral runoff degrades the Alamosa River’s water quality, so conserving cold-water headwaters like Cliff Lake is key to restoring the health of this alpine stream.
At a lofty elevation of 11,620 feet, Cliff Lake is named for the sheer cliffs of Cornwall Mountain that tower over its western shore. Mature evergreen forests and mountain meadows flank its eastern banks. Spanning 800 acres off the northeast shore of the lake, the undeveloped Cliff Lake property includes the outflow of Castleman Gulch and is the only portion of the lake not managed by the national forest. The property includes over 200 acres of old-growth spruce forest and nearly a mile of Castleman Gulch itself. This spectacular, pristine and incredibly fragile high-mountain habitat is critical for wildlife like Rocky Mountain elk, Rocky Mountain bighorn sheep, mule deer and the endangered Canada lynx.
NEW AND IMPROVED ACCESS TO CLIFF LAKE AND THE NATIONAL FOREST
Transferring the Cliff Lake property to the national forest will also reestablish outstanding recreation opportunities in a beautiful alpine lake setting. Public ownership will allow visitors to access the lake to hike, view wildlife, hunt, cast a line in the emerald-green waters and enjoy expanded access to the surrounding national forest.
Now that WRC has purchased the Cliff Lake property, our goal is to secure funding through the Land and Water Conservation Fund to transfer it to the national forest. The effort complements our ongoing, landscape-scale conservation work at the 45,952-acre La Jara Basin property, which is just five miles from Cliff Lake. Taken together, our efforts will have far-reaching impacts for fish and wildlife, and for people, who will always be able to access some of the state’s most cherished natural landscapes.
