Riffe Lake is a 23.5 mi (38 km) long reservoir on the Cowlitz River in the U.S. state of Washington. Originally named Davisson Lake, it was created in 1968 with the construction of Mossyrock Dam. The lake was renamed in 1976 after the community of Riffe, which was inundated by the lake.FishingFishing in Riffe Lake can be very good. Species include rainbow, brown trout, landlocked coho, bass both large mouth and Small mouth, bluegill,crappie, and perch.