Worth stopping by if you are in the area. I went to a star party here which was pretty cool.
From Los Angeles, take the I-5 northbound to the Antelope Valley Freeway (14 east). Drive about 25 minutes, exit right at Agua Dulce Canyon Road and turn left. You will drive under the freeway and across the Sierra Pacific Railroad and wind uphill until you reach Escondido Canyon Road. Make a right turn and you will see the park off to your right.
In this location they film a lot of western films. When staying in L.A you can see the rocks in a commersal. And I saw them in Austin Power 1.