Get your hands on some limestone bouldering at this spot. There's actually two locations for bouldering in this area, Columbia College and Columbia State Park (about less than a 10 min. drive from Columbia College), but I made this specific adventure for climbing on the college. 

GPS Coordinates for parking:
38.02931, -120.38925

I suggest going on a weekend or when school is not in session. On the weekend that we went there wasn't anyone at the kiosk, so we didn't have to pay if there were any fees. Parking was easy. Lots are big. 

There's about 75 problems, ranging from V0 - V10. I highly suggest picking up a copy of the Northern California Bouldering guide. Best time to go is during spring and fall. Summertime is hot and during rainy winter, the rock takes longer to dry. 

Be careful of poison oak.

Climbing at The Arboretum area:
(GPS Coordinates: 38.03311, -120.38935) 
Total approach time from parking lot to main bouldering coordinates area is 10 min.
From the parking lot, walk up and around the lake on the left side. The last building is the Natural Resources Building, and there's a well-marked trailhead to the Arboretum. Take this trail downhill until you come to the coordinates. 

Some notable climbs:
White Elephant (V1)
Welcome Wall (V5)
Pope Dispenser (V7/V8)
Lobster Claw (V5)
Double Cracks (V4)
Triple Cracks (V7)
Cave Crack (V2)
Gold Wall (V4)
Icarus (V8/V9)

Where to Camp:
Closest place we found to camp was at Marble Quarry RV Park. They're 15 min. away from the college. Their tent site area is incredibly small. They have restrooms, a pool and convenience store. We paid $26 per night.