“A great descent from Joshua Tree forest through monzogranite boulder mountains.
— Peter Bugg
I have not run this trail, but the terrain is pretty smooth, and nothing too steep. The only part that would be less than ideal is a few sections in washes in the northern area of the trail that are a little sandy and slow.
From the southern trailhead, where there is a backcountry board, sizeable parking lot, and bathrooms (but no water) the trail goes north, descending gradually through a classic Joshua Tree forest. After about 1.2 miles, there is a side trail to Willow Hole, which is nice, but not amazing. If you stay on the main trail, it continues through the J-Tree forest until it starts to descend more quickly though monzogranite boulder piles that are typical of the northern edge of the park between the towns of Joshua Tree and 29 Palms.
The last mile or so drags on a little bit, as you can see town, but as there are few markers, distances can be deceptive so you don't know how far you have to go to get to the northern parking lot (no water or bathrooms, much smaller than southern parking lot). I recommend doing this with two cars shuttling, as opposed to an out and back.
Lots of J-trees, chollas, and hedgehog cactus. Very classic Joshua Tree.