Denny Lake is located in the San Juan Mountains in southern Colorado and offers excellent fishing opportunities for trout, including rainbow, cutthroat, and brook trout. The lake is surrounded by beautiful scenery and nearby activities include hiking and camping. Fishing tips include using dry flies, nymphs, and streamers, and fishing early in the morning or later in the evening for best results. The best time to visit is during the summer months, with average temperatures ranging from 60-80 degrees Fahrenheit. Get driving directions.