Bear Canyon to Salt Creek
Bear Canyon is a three-mile singletrack on the south slope of Mount Nebo, about 10 miles from Nephi. I recommend this trail as a 12.7-mile loop ride by climbing the scenic Nebo Loop Road to the top, then bombing down 2100 vertical feet on singletrack over 3.1 miles. There are some very technical creek crossings.

The ride starts from the Bear Canyon Campground in Salt Creek Canyon, found right at the end of the Salt Creek Road. This road forks off the Nebo Loop near the southern end. Park just before the bridge, outside of the campground, so you won't have to pay a fee. (Or camp and ride the next day.)
Start by retracing the Salt Creek Road, two miles with a very gradual downhill slope. Then fork left and begin climbing the Nebo Loop Road. The Nebo Loop is famous for its beautiful trees and mountain vistas -- especially in late September to early October.

The slope of the Nebo Loop makes for an easy spin. Constantly changing vistas will distract you from the steady uphill. Stop at the occasional pullout. Take the quick hike to the Devil's Kitchen. Before you know it, you'll have completed 7 miles of climbing, gaining 2200 vertical feet.

Watch for a log-fenced parking area on your right, just as the road turns to the left. There should be a "Bear Canyon" trail sign. The trail is on the left side of the road, right at the apex of the turn.
Drop off the road and begin your downhill. The first mile is fairly mellow, with aspen alternating with maple and fir.

The middle mile of the downhill gets a little trickier. There will be a few sudden plunges into the rocky creekbed, where outcrops of rough conglomerate are ready to trip you up. All but experts will walk a few of these crossings.

The last mile of the downhill is fairly pleasant cruising on buff trail. At 1/4 mile from the end, you'll come to a metal gate. Go through, and pass several primitive camping spots until you cross the bridge to the parking area.
It's possible, but very difficult, to ride the Bear Canyon trail uphill. It will average 700 vertical per mile. It's a fun climb, and can be done with a few very short push-a-bikes, but only the strongest climbers should consider this.

Riding notes, from Bear Canyon Campground:
0.0    Head back down Salt Creek Road
2.1    L on Nebo Loop Road, begin climbing
8.2    Devils Kitchen on L (take a hike)
9.6    Turnout on R, drop LEFT on ST
         Head down Bear Canyon Trail
12.6  Through gate, past camping spots
12.7  Back at bridge

Getting there: From I-15 in Juab County, take the Nephi 100 North Exit. Turn east, toward the mountains. Drive about 6 miles up the canyon, then turn left on the Nebo Loop Road (Scenic Byway). Drive another 3.5 miles on the loop road and turn left on the Salt Creek Road toward Bear Canyon Campground. Go 2 miles up the road, and park on the right just before the campground entrance.

Water:  At the campground
Toilets: At the trailhead, plus Hells Kitchen on Nebo Loop Road
Camping:  Bear Canyon, nearby Cottonwood campground.
Nearest bike services: Payson