Emerald Lake is not in the Wallowas, nor is Crystal Lake. There is no easy access to anything at Riggins from here. Emerald is in a Wilderness area on the idaho side of the Snake River. Joes gap is just a pass one hikes through on the way to Emerald from Black lake, a 3-mile hike. Crystal lake is a difficult hike several miles away. It is indeed a beautiful little lake. As far as fishing, I have always had good luck fishing using Panther Martins as a lure.
Says R Fisk
How is the fishing? Says Dan Rackham
This lake is so wonderful. A spree to Purgatory Saddle is always fun, and on a good day you can take a hike along the Rapid River Trail.