The Cow Cove Petroglyphs are located east of Baker, California in the Mojave National Preserve.
To get there, take I-15 Exit 272, which is 26 miles east of Baker. Head south on the Cima Road for an hundred feet of so and go right onto the Cow Cove Road. Continue for 8.2 miles and turn right on a spur road that leads to Cow Cove. You should be able to drive about 1 mile before you have to park and begin hiking the last half mile to where the petroglyphs are along the bluff.
Included with this post is the GPS file and map that we plan to use for our first visit. If you don't want to wait for us to get around to it feel free to try the GPS file and map for yourself. With no guarantee, of course, but they most often prove valuable for us.

