The trail from the John Muir Trail to the lake is relatively flat and unobstructed, so it offers a nice path to run on. The trail can be wet in the early spring, so mud can be a challenge.
To reach this trailhead, park on the side of Tioga Road, just west of the Tuolumne Meadows Visitor Center. There are bear boxes at the trailhead for your food and ice chests. Due to it's popularity, there may be many cars parked along the road, so you might have to run a little to reach the trailhead.
To access this trail, start running on the John Muir Trail for roughly 3 miles. The John Muir Trail climbs steeply through a lodgepole pine forest, levels out and crosses several branches of Cathedral Creek, and then climbs steeply again until the trail levels out at the base of Cathedral Peak. At this point, the John Muir Trail widens and becomes sandy as it continues to the junction of the Lower Cathedral Lake
Trail, where the Lower Cathedral Trail begins.
Turn right (southwest) and follow the trail for about .5 miles through areas of wildflowers until you reach the bench of the bedrock of the lake. You may need to rock hop a small creek or two in the meadow, depending on the time of year. There may appear to be a rust line on the rock, which indicates the high water mark when the meadows flood in the early part of the season as the snow melts. You can find a place on the rock here to relax and warm up in the sun, or continue to work your way around on the right hand side of the lake, following the trail to it's terminus. While fishing may be poor here due to its popularity, this relatively shallow lake offers many opportunities for swimming, sunbathing, and simply relaxing on the warm rocks along the edge of the lake. You won't be alone, as this is a popular trail due to it's proximity to Tioga Road and the John Muir Trail, but there is a large area to spread out along the shoreline.
Once you arrive at the lake, turn around to get sweeping views of Cathedral Peak, rising like a spire before you. If you run to the end of the trail on the right side of the lake to explore the lake's outlet, views of Polly Dome, Pywiack Dome, Mount Hoffman, Tenaya Peak and some of Tenaya Lake can be seen.
Once you are done exploring, you can take the trail back to your car, or if you are backpacking along the John Muir Trail, continue on your way to your destination for the evening.