Hidden Lake is a gem consisting of 44 sites: 3 are directly on lake side, but the remaining are located on Skyview Loop. There are trails linking them together and an ampitheater as well. The fishing is pretty good, and salmon migrate from Skilak Lake. The lake is also home to lake trout, rainbows, and dolly varden. Motorized boats are allowed, but we canoe this lake regularly: look for beaver, loons, raven, and bears. The CG is primitive with no hook-ups, but it does have a dump at the entrance. The sites are deep and wide ( excluding the lake-front ones, which are a little cramped). Reservations are not allowed in the KNWR so the sites are all first-come first-served. The CG gets a decent amount of day use, but I have never seen it packed. Hidden Lake is accessible by the Skilak Lake Road is approximately 3 miles south from the north entrance ( Cooper Landing) and 15 miles north from the Sterling side. There are lots of amazing day hikes off Skilak lake Road; you could spend an entire summer here just hitting the various lakes and trails. $10 / night, vault toilets, hand pump water, open year round. Hidden Lake can " blow out" in the summer so be prepared: calm mornings can lead to widy afternoons with whitscaps on the lake. Be prepared, and put safety first.