In the northeast corner of Lassen Volcanic National Park lies a relatively unknown and unused lake. We have paddled there for years and have never seen more than 2 or 3 other paddlers on the lake besides ourselves, even on weekends.
The lake is shaped like an upside-down L, and the only road access is to the toe of the L. The rest is actually inside Wilderness. Power craft are not allowed, and the water is crystal clear all the way down. About 2/3 of the lakeshore is volcanic lava flows with bizarre shapes and forms. The middle of the upright part of the L is an archipelago of small lava islands with many channels and hidden coves to explore (caveat there may be jagged sharp rocks just below water level that will reach out grab your hull. Keep one eye on the water directly in front of you).
The lakeshore that is not lava, is forest and a hiking trail follows the eastern shore. The southern tip of the lake is a bit more shallow and you can put ashore for a break. The Park says you can overnight camp at the southern end of the lake. Other than the campground at the roads end, there really is nowhere else to put ashore.
The trail system branches at the south end of the lake and you could do some short hikes from there. Exploring the lava beds by foot is possible, but is extremely rough and jagged. Dont try it in sandals or paddling shoes. Regular hiking footwear will be needed.
There is not real good fishing on the lake. The water is too clean, no basis for the food chain. So there is not a large wildlife population on the lake. A few waterfowl. We have spotted 1 otter in the water in all the trips there. We go for the scenery. The contrast of the crystal clear water, lava fields, and forest make it a memorable place to just paddle around.
About 2 miles of trail south of Butte Lake lies another large lake called Snag Lake. The NPS does not allow wheeled carts on the trails, so getting to that lake requires portaging on your shoulders.
These lakes are definite Summer only destinations; Frozen and inaccessible during winter.