This hike is in the Paria Canyon-Vermilion Cliffs Wilderness.
Cobra Arch is one of the most unusual I've seen and the Middle Trail into Buckskin Gulch looks pretty good and doable. With just day packs it looks like a piece of cake (about 100 vertical ft.), but we didn't have time this go 'round to enter the gulch.
I've been in the bottom of Buckskin several times, but had never seen it from the rim until now. It's DEEP (up to 500 ft.)! Which I could kinda tell from the bottom.
Route to trail head: Take route 89 east from Kanab, Utah or west from Page, Arizona. Between mile posts 21 & 22, immediately east of Paria River Guest Ranch, turn south on gravel road FR #750. Stay on the most main route, which is occasionally marked "750" to the Middle Trail. The trail head is just past a fence line, on the south side of the road, 7.8 miles from the paved Hwy. 89. The last mile is sandy and 4WD at certain times of the year. I made it all the way in 2WD.
Oh yeah, Long Canyon, which is about a mile from the pavement, looks to have some pretty neat narrows to explore sometime. It's not really colorful probably, but it is tight.
Hiking route from the Middle Trail head: Progress south on the trail for a few minutes to where the fence is down (before 1st downgrade) and turn left or east on a well worn trail. Follow the rim for about 45 minutes where a trail leaves the rim to the right and heads down slope. In another 45 minutes reach Cobra Arch. (So it's about 1 1/2 hours to the arch, 45 minutes on the rim and 45 minutes slogging through the sand to just below or south of the arch.) After visiting the arch head southwest toward the big gash in the earth which is Buckskin Gulch. Basically rim walk the north side of the gulch until the Middle Trail is intersected. This should take 1 1/4-1 1/2 hours from the arch. You'll get there. Then take the Middle Trail north and uphill back to your vehicle (let's say 1 to 1 1/2 hours again). With sightseeing, multiple stops for picture taking, and looking into Buckskin at various points, the whole loop took us 4 1/2 hours at a leisurely pace. WARNINGS: If looking into the slot canyon from above be extremely careful for two reasons: 1) Anything kicked or dropped or thrown into the canyon may kill someone below. 2) The slot canyon's rim is very disintegrated and flaky and if you are on a slab that breaks or if you lose your footing you are one dead person for certain.
Do take the time to look at the gulch access at Middle Trail. There are some good petroglyphs to see without leaving the rim or downclimbing.