Lost black travel backpack near Russian Gulch State Park in Mendocino County containing a water bottle, first-aid kit, and green notebook.

I lost my black travel backpack while hiking the trails in Mendocino County. It has some important items inside, including a water bottle, a first-aid kit, and a small green notebook with my notes from the trip. I last remember having it near Russian Gulch State Park. Please let me know if you come across it!