Found this blog posting from some folks who went backpacking to the dome country at Anza-Borrego in Southern California. Includes some nifty pix, plus this:

It’s about a 3.5mi backpack from the trailhead w/ a bit of elevation gain. We hiked in during the afternoon and it was nice and cool – which was good because we were each carrying 8 liters (that’s 17 lbs!) of water, plus our backpacking gear.

Basic backpacking calculation: You can carry much more if you walk much less. Anza-Borrego gets mentioned in a lot of the Trail Journals accounts of thru-hikers heading northward in the spring, when it’s already a fiery furnace down there. Much cooler now, though — just the thing to give the one you love for Christmas: a weekend among rocks!

More on Anza-Borrego (which is the largest state park in the state, the only one bigger than our beloved Henry Coe) at the State Parks Page.