This trail is the Coconino Forestry Service flagship trail. I have hiked this is the middle of summer as well as in the fall. I would say the fall is definitely the best. The Aspen were just at their peak of fall color and the air was cool and crisp. Who could ask for anything more?
The hike is mildly strenuous because of the elevation. It starts out at 9300' and drops to 8800' at the end. It's best done in a two car shuttle. The second car can park at the Weatherford trailhead. I believe you can reach this trailhead from Friedlein Prairie Road, which is blocked off at a point. I don't think the walk is too bad though, and you can park where the roadblock is.
This trail is the best the San Fran peaks has to offer. There are beautiful fir, spruce and aspen forests, meadows. Early on the in hike, there is an interesting little cave, some basalt cliffs. You'll pass through Friedlein Prairie. This is visible from Flagstaff, it's that big triangle you see when you look up at the peaks. If I even make it this far, I'm lucky. This is a tougher hike that you might think because of the elevation. I have never gone all the way across as I suffer from elevation sickness and usually poop out at about 3 miles. At one point you start going uphill at a fairly respectable climb. It's in a meadow and the view is fantastic.
It's always a good idea to get acclimated to high elevations before a hike like this. One person in my hiking group this time had hiked in the Himalayas, so this was nothing for her. If you only have one car, Freidlein Prairie is a good place to turn around. It's the 4 mile mark. If you are gonzo, you can make it all the way to the Weatherford Trail trailhead and turn around, knock yourself out! I know it would me.....
Remember, please keep the dogs on a leash and if I catch you carving on an aspen, I'll pinch your head off.