Campers at Lake Mendocino and Lake Sonoma must vacate the parks by 9 a.m. Monday because of the federal shutdown, the Army Corps of Engineers said Friday.
Dam operations and the fish hatchery at Lake Sonoma will remain open, but the parks will be closed to visitors and locked Monday morning.
No new reservations will be accepted as long as the shutdown lasts, but campers with reservations may request refunds.
No day-use visitors, such as hikers, will be allowed in the parks and any scheduled special events will be cancelled as long as the shutdown lasts.
The Lake Sonoma Marina will remain open, the Corps said, because it is a self-sustaining concessionaire.
The closure includes the public boat ramps at the lake, meaning boaters hoping to make day trips on the water will have to launch from the marina's ramp, which charges $15 per day for access.
To request a refund for a Corps-operated campsite, call (888) 448-1474.