Given the creek crossings and steep/loose initial ascent, this doesn't stand out as a great trail run option, but you'd probably have the trail to yourself.
From Gros Ventre Road, head south on Crystal Creek Road to the kiosk and trailhead. The trail starts with a creek crossing of Crystal Creek, which can be fast and high with snow melt so be prepared to explore downstream for wider, shallower sections.
Once across, head south through the meadow toward the first forested hill climb. This section is steep and loose. Take your time and watch your footing. From the top, continue south past a Lookout Spur
with views into a small, red cliff canyon surrounding a section of Crystal Creek and views of the mountains to the north. Descend toward the valley below with one more creek crossing, which is relatively easier than the first.
A popular spot for anglers, here you'll find many pools, bends, and holes to fish with expansive views across the valley. Continuing southeast, the trail maintains a nice, flat grade with a lingering feeling that you aren't the only animal around. After around 2.4 miles, the trail ducks into the intermittent shade as it begins to climb a little toward the confluence with Jagg Creek and the Jagg Creek Trail. There are two intersections to continue on this trail. The first can be taken in either direction, left or right. Heading right goes down to the creek with more creek crossings and the left goes to the intersection with Jagg Creek Trail.
At this second intersection, just before the four-mile mark, you'll come to an intersection with Jagg Creek Trail. Head right across the creek toward the large Crystal Creek landslide to the south, which marks the northern end of the ridge up to Crystal Peak (10,968'). The trail continues to bend around the eastern base of Crystal Peak along the creek with access to the West Fork Crystal Creek Trail #4017 around the 8.4-mile mark, which heads west below Pyramid Peak (11,098') to the Flat Creek Trail #4015.
Finally, the trail tops out at the intersection with the Swift Creek Trail #4020, Shoal Falls Trail #4119, and the Gros Ventre River Trail #4081
Sagebrush, pine, buckwheat, native grasses and forbs.