This somewhat forgotten lake is nestled in a cirque feeding the Minam River way up high. It is a beautiful run into the lake that is a visually-compelling finish as the trail winds through glacial formations down to the lake. Pop Pass is also really ascetic and as you reach the top you're greeted with a great view into the interior mountains like The Matterhorn. Not many visitors make it to this lake each year.
The access is a single trail that terminates at the lake, but officials have tried to terminate the trail altogether as it isn't on many maps anymore. There is no signage or trail entrance, but you'll maybe find a rock stack just after passing Cached Lake on the Main Eagle Trail. It doesn't follow the original route shown on old maps, but has a new route that is difficult to find especially at the beginning. There are some--but not enough--rock stacks through the original stretch but as you get up higher near the pass is becomes much clearer and is surprisingly easier to follow after the pass, but the cairns are definitely beneficial. It is fairly open country, so if you lose the track zig to the right and then zag up the mountain toward a low point between the brown rock and white rock and eventually you'll probably find the series of cairns you can trust the rest of the way.
Notes
0.0 Trail begins at mile 7 on the Main Eagle Trail a few hundred yards past Cached Lake.
1.1 Pop Pass
2.1 Pop Lake