At the west end of Birchcrest is a locked gate. The developer says keep out, but mountain bikers are usually not bothered by the owner or the sheriff. Motorcycles or 4X4's will be asked to leave. Go north for apprx 5 miles to Poway.
Trail signs are at each intersection.
Martha's trail leads back south in a loop to the main trail. The trail's still open and a good ride for any skill level. Take 52 to Mast Bl. in Santee and turn left. You will see a school on the right and hills on the left. The trail is on the left just before the first house, and just after the school parking.