There is a primitive campground on the SW corner of McKelvie National Forest (on 16F just as it leaves the SW corner). Big pine trees, and usually deserted. Pretty sure there is a water pump there (really good Sand Hills water).
Nearest gas is probably at Merritt Trading Post (near the Merritt Reservoir dam) SE of the Forest.
"It's sorta like a combination of camping in your Grandma's back yard, and a Frat party. " --fifthcircle