The entrance to this hike is super tricky... No one in Yosemite knows about it. Make sure you take Cherry Lake Road. From Yosemite/Hetch Hetchy, you take that all the way down to the trailhead at the bottom of the valley (20 min drive from the Mather Camp). The trailhead is actually called "Stanislaus National Forest Trailhead" and is not correct on Google if you search Preston Falls (but the directions are correct using the AllTrails app/map). When you are ready to head back, you go to the top of the road and turn right at the stop sign to get to Hwy 120. Just print out the map using All Trails before you get there bc there's no reception out there. I've posted a picture of the Trailhead sign so you'll know when you've reached the right place.
Trail itself was great, runs along the river mostly, moderate is accurate. You will have some flies in your face for the first half hour or so which is annoying. We went early October and it was still quite warm but not busy at all. By that time, the falls are supposedly dried up but the trail itself is still beautiful to hike. 40 percent shade, 60 percent in the sun. The trail itself must be more than 8.5 miles out/back bc we reached 4.3 and were definitely not at the end. Maybe it's 9-10 miles total. I'll post a picture as well of the "mini falls". I would suggest stopping there and turning around because after that point we spent 45 minutes walking through low weeds and scratchy branches which scratched up our legs (had shorts on) and was irritating to walk through. After that point, it seemed that not many people continued since the way wasn't very clear (branches weren't cut back).
There are some places to get in the water as well as mini "beaches" with sand!!!
Erik L. on Lookout Point Trail
Hiked in late May and the wildflowers are amazing. Interesting meadow in the saddle. Nice panoramic view at the top, including Hetch Hetchy Lake, O'Shaughnessy Dam, and Wapama Falls.
Relatively easy walk, moderate uphill for the last half.