Manzanita Lake is a lake located in Lassen Volcanic National Park.

Manzanita Lake was formed when Manzanita Creek was dammed 300 years ago by a rock avalanche from the northwest slope of the Chaos Crags, which also resulted in the debris formation known as Chaos Jumbles.

[1] The area around the lake features the Loomis Museum, a campground, and the Manzanita Lake Naturalist's Services Historic District.

Located near the park entrance, the lake is open for fishing and has rainbow, brown and brook trout.

[2] Manzanita Lake has a warm-summer humid continental climate (Dsb) using the 0 °C isotherm or a warm-summer mediterranean climate (Csb) using the -3 °C isotherm with short, warm summers and cool winters, with most precipitation falling in the winter months.