The butte more or less blends in with the rest of the terrain and the only reason why this particular feature has its own parking area I believe, is because of the ancient granuaries located around the cap.
There isn't much, aside the grain storages, that sets this particular butte apart from the others in the park of which, there are many. Save for the fact that it does offer some great views of Taylor Canyon to the north.
There are three granaries that exist at the top of the butte that were used by the long-departed Anasazi Indians who once inhabited the area. There is also a smaller butte adjacent to Aztec Butte (unnamed) that also contains a granary. These man-made features alone are actually quite worth this little side-trip.
Getting ThereOnce past the entrance station to Canyonlands, "Island in the sky" district, travel 7 miles (south) on the main throughfare past the visitor center. At ~7 miles, a junction for Upheaval Dome/Green River Overlook will appear. Take this right-hand turn and proceed for an additional .9 mile and turn right into the small signed parking area. This is Aztec Butte.
You will need to pass the spur to the Green River Overlook (worth having a look!) and Willow Flat Campground (located on the left).
The visitor center is 1.1 miles from the entrance station.
MAPS: Trails Illustrated, Island in the Sky (Canyonlands)
USGS, Musselman Arch and Upheaval Dome
Route DescriptionThis is a very basic and straight-forward trail. The first half-mile or so is nothing more than a sandy walk around the base of the smaller unnamed butte. Once on the other side of this smaller butte, the summit of Aztec Butte is immediately in front of you and only .25 mile and 200 vertical feet away. There is a path marked out to prohibit erosion.
You could probably just "spider-walk" below and around the top lip of the butte to get different vantages but be aware the butte retains a fine coating of sand. So if you slip, there isn't much to grab onto. I wouldn't recommend this unless one could find holds. The north side gets quite steep but holds two granuaries. The easiest way to attain the summit cap is from the southeast.
To gain the top of the smaller unnamed butte, it is also only a .25 mile spur to its' top.
Expect roundtrip hiking time to set you back only 90 minutes or so. This is a super-quick side trip worthy of the time.
Parking area: 6082ft.
Aztec Butte: 6291ft.
USGS Maps: Musselman Arch & Upheaval Dome
External LinksThis is a short video pan I made from atop the butte. Trust me, it's nothing special but it does show some of the terrain. Enjoy! Aztec Butte
GJHikes -A pretty good website with decent pictures and good beta.