The East River is a freestone river that drains out of Emerald Lake, which is located at about 10,500 feet in the Rockies near Crested Butte. It flows down through the valley to Almont, where it joins the Taylor River. Most of the river flows through private property, and there is limited public access. The most popular public access area is at Roaring Judy Fish Hatchery, just a few miles north of Almont.
The East River is a low gradient river with nice long pools and plenty of riffles. The East is easily waded and a very enjoyable river to fish. The section by the hatchery is wild trout water with special regulations (flies only). The river holds nice rainbows, browns, and some cutthroat. Due to the limited public access, it can get busy on this stretch, especially during the salmon run.

Like the Gunnison and Taylor, the East River gets good insect hatches and provides anglers with plenty of dry fly fishing opportunities during the summer months. The peak fishing season is from about late June (after run-off) to late September. Many anglers will pursue kokanee salmon on the East River during September and into October. An 8 to 9-foot, 4-weight or 5-weight fly rod is a good choice for the East River. A 5-weight or 6-weight outfit is recommended for kokanee.