The photo below shows part of my favorite section which runs from Lake Powell Blvd. just below the Quality Inn across from McDonalds, around to Lake Powell Blvd. near Aspen St. across from the college. The trail is mostly on a shelf with sheer dropoffs and offers excellent views of Glen Canyon Dam, the Highway 89 bridge, the fissure which contains the Colorado River downriver from the dam, a country club, and various stores. The trail is mostly clay with some areas of slickrock and some of loose sand, and is probably about 15 miles in length when the top loop is included.
The extra loop of the white trail shown at the top of the above map (closest to Lake Powell) is called the Discovery Trail and encircles a hilltop, with extra tracks cutting through the center up and over the hilltop. The photo below is taken from there. You can see the red soil of the trail at the bottom of the photo where I am standing, the Glen Canyon Dam with Lake Powell backing up behind it, and if you look carefully, you'll make out the bridge just this side of the dam. The lush green in the foreground is the golf course that is below the trail in this section.
Here's a photo of Lake Powell with the dam in the background. The lake as seen here is 97 feet below normal pool level due to a multi-year drought, and the white cliff faces are stained with calcium carbonate because they have been under water for many decades. If the water pool were at normal level, you would see far more blue water and the channel would be much larger than seen here.
The next four photos give you an idea of what the trail is like. It is right on the edge of the cliff line, often with a hundred feet fall-off. The sights are to-die-for, but don't lose your concentration or you might pay that price!
The trail in the next photo doesn't end there, but goes between the rocks that seen to be a dead end. You can see the trail continue beyond.
This is an interesting solution to the problem they faced when there was no way to dig a shelf for the trail. They erected a steel platform with a ramp at the far end for you to bike on. Clever! And safe.
The eastern leg of the trail borders the Navaho Reservation and gives distant views of mountains and the Navaho Generating Station to the east. You can see the tall smokestacks in the photo below, far off in the distance in the upper left, with Navajo Mountain behind them.
The trail is again on a shelf below the rim and zigzags around water runoff canyons as seen below where the trail turns left and then later back to the right. The airport property is to the right up on the rim and has a service road along its fence line which I mistakenly thought was the trail my first time around the loop, but it is in bad shape and the actual trail is far superior.
Occasional sections as below were in a rough shape, and with the steep dropoff you had to take care not to crash...
...which I did my third time biking the trail. I lost concentration, distracted by the views, and took a tumble. I was on the ground with the bike atop me. You can see one of my white water bottles on the ground behind the rear tire. After 30 seconds or so I decided to try to get up to see if all of me came with. Fortunately I wasn't at a steep dropoff. I had a few scrapes and bruises and a bit of blood oozing out, so I washed everything with my kerchief and water from my water bottle and got back on the bike and continued. But the bike was damaged and the rear shifter wasn't fully operational and the front chainring was bent, so the bike wasn't cooperating very well. I got to the first exit point and headed back to my motel room, disappointed that my third year riding here had ended after 10 miles instead of 15.
Actually, truth be told, one of the first things I did was take the photo and then I put it up on Facebook with the caption, "Maybe I'm getting too old for this mountain biking stuff." My good buddy and former colleague, the late, great Rich Bokor, immediately responded with his usual sense of humor poking me for being older than he was, saying, "Yes, you are too old, Chuck."