Part I. of II. Animas River, CO.

Animas River is a 126-mile-long (203 km)[2] river in the western United States, a tributary of the San Juan River, part of the Colorado River System. The Spanish named the river "Rio de las Animas Perdidas", "River of the Lost Souls". It is also the last free-flowing river (un-diverted) in Colorado. The river's free-flowing status will soon end as the Animas-LaPlata Project nears completion. The project will pump water over a low pass to fill a reservoir, Lake Nighthorse, in Ridges Basin to satisfy Southern Ute tribal water rights claims associated with the Colorado Ute Settlement Act amendments of 2000.
The Animas River rises high in San Juan Mountains of Colorado at the confluence of the West and North forks at the ghost town of Animas Forks and flows south past the ghost towns of Eureka and Howardsville. At Silverton, the river flows into the Animas Canyon. The Durango and Silverton Narrow gauge railroad follows the river through the canyon to Durango. From Durango the river flows south into New Mexico through the town of Aztec to its confluence with the San Juan River at Farmington.
The only major tributary of the Animas River is the Florida River which confluences just north of the Colorado–New Mexico border.
The Animas is a freestone fishery well populated with rainbows and browns and a few cutthroat and brook trout. Fly fishing the Animas is available year-round due to moderate winter weather. Steady insect hatches of midges and beatis occur In the winter and spring months. In late spring, summer and through fall the Animas is alive with caddis, PMDs, tricos and hoppers. Animas trout are strong and average between 12 to 16 inches. Larger trout in the 17 to 22 inch class are also available for the anglers willing to put in the time. Brown trout as large as 36" have been caught from the Animas.