Cahuilla Creek MX Park is located approximately 27 miles East of the 15 freeway on Highway 371 in Anza, CA
From the I-15 freeway at Temecula: Take hwy 79 South (towards Indio) and go about 17 miles to hwy 371.  Turn left on 371 and go around 10 miles and the track will be on the right side of the road. You can see the track from the road, and you should be able to see the orange fencing. If you get to the casino, turn around because you went too far.

For more detailed directions, you can call Cahuilla Creek MX park at 951 926-4646.