Why is the Grass Valley gate closed, I would love to hike but can't get in?

State park

10791 E Empire St, Grass Valley, CA 95945, USA

Grocery store

105 Neal St, Grass Valley, CA 95945, USA

Park

660 Minnie St, Grass Valley, CA 95945, USA

Breakfast restaurant

746 Taylorville Rd, Grass Valley, CA 95949, USA

Bank

134 S Church St, Grass Valley, CA 95945, USA

Fast food restaurant

11954 Nevada City Hwy, Grass Valley, CA 95945, USA

Laundromat

871 Sutton Way, Grass Valley, CA 95945, USA

Home improvement store

Nevada City Highway, Yuba River Ct #120, Grass Valley, CA 95945, USA