There happens to be a good pit very close by. I shoot there all the time.
It's hard to describe, but it will help if you have this map:
MAP LINKPlainly Visible are the reservoir (bottom right) and the rock pit (upper left) Switch between the satellite and street maps to figure out where it is.
Take the road Nfd 4810 north out of Rock Creek Res.
Turn left onto the paved.
Follow that for about a mile and a half to two miles.
Turn right onto the dirt road.
Follow that as it winds around and down the hill.
Watch out. At the bottom of the hill are two nasty washouts. If you don't have some some sort of truck, I wouldn't try it.
Then follow the road to the right and up a steep hill with lots of loose rock. Might need a truck here too.
There are two pits. I mostly shoot at the upper pit, but there is also a lower pit that can be found by driving past the first pit and following the road to the right.
Satelite map found
HEREI don't think I have GPS coords anywhere.
I would meet you there, but I work weekends...