There are three locations to access the SJRT: 1. The River Gorge (Squaw Leap); 2. Wellbarn Road; and 3. South Finegold Recreation Area, at the north end of Sky Harbor Road.
By far, the most popular is S. Finegold. I have been riding the trail from there since 1997.
Park on the road, then descend to and across a small parking lot. Then, take a hard right and head up the hill. Enter through a cow gate, and then climb for about 1 mile, with brief reprieves here and there along the way. This is a very challenging climb, so don't be surprised if you walk a bit if you're not in top shape or have the skills to get up and over rocks and traverse ruts following rainy season. Sections can top out around 30% grade.
Enjoy a rest and great views at the top of the climb. Then, head south for rolling terrain for another mile.
Mile 3 begins with a long descent with one really steep section that you might want to dismount and walk if you're not at least a good intermediate rider. Continue descending to a second cow gate at mile 3.
After that, the trail is essentially rolling, with some short steep sections, meadows, small stream crossings after rain, following the lake/river.
At 10 miles out you encounter a bathroom where the trail meets the end of Wellbarn Road. Can turn around there, or head up the road and then locate the trail sign on the left to continue the trail to the Gorge area, crossing a small bridge along the way.
This is a world class mountain bike trail, challenging for the best riders but not too intimidating for beginners. The scenery is incredible. Look out for bald eagles, deer, tarantulas, and cows in the winter and spring.
I would recomnend the biggest knobbiest tires you can get. The more traction you have the more you can stay on the bike and ride up the hills. Less skidding on the descents, too.