Access and Camping
Both canyons are located in San Rafael Swell, off the Highway 24 (north of Hanksville and southwest of Green River). Turn and follow signs towards Goblin Valley State Park, and just before entering the fee area, turn west and follow signs to Little Wild Horse Canyon. There is a dirt road passable to all vehicles in the dry weather (the road is paved now per Bob Sihler 10/11). There is no fee for exploring these canyons.
There is a luxurious campground inside the Goblin Valley state park (including warm showers!). The charge is 12$ per night, or you can camp off the dirt road past Goblin Valley for free, or sleep at the trailhead (if you do not mind stinky toilets).
Little Wild Horse canyon
Hike starts by walking in the wash, past a grove of cottonwoods. There is a section which appears as a dead end, you just have to climb on the side of the canyon and continue towards to a fork. There is a sing pointing towards Little Horse and Bell canyon. We started our hike via Little Horse.
The hike itself is pretty easy. The canyon is usually dry, but we were visiting after a rain, so we had to wade through some watery sections. It was actually very refreshing.
Images from Little Wild Horse Canyon
Between the canyons
There is an open section between both canyon. This part is very exposed and can be very hot in the summer (not much shade). So bring a lot of water with you.
Bell canyon was not as scenic and narrow as Little Wild Horse, but still very pretty. There were interesting rock formations along the way, which my son enjoyed exploring.
Images from Bell Canyon
Time needed and legth
We took a leisurely hike and it took us about 5 hrs. I think you can run it in less than 2 hrs. The total distance is 8 miles.