Ten LakesThe trailhead is 32 kms outside the Valley on hwy 120 going east (Tioga Rd). It is marked T14. If you are heading east, it is located right before the Yosemite Creek picnic area (after the White Wold campground). If you are heading west, it is located after the Porcupine Flat campground. The trail heads north, so it is on the left-hand side of the road if you are driving east.
The elevation at the trailhead is about 2500 meters. The Ten Lakes trail heads mostly north. After 3kms it intersects with the trail coming from White Wolf. After another hour of walking, the trail enters a meadow. Bear left in the meadow. Then the trail climbs up very steeply, coasting the waterfalls. after about one hour, the trail forks: right for Grant's Lake, left for Ten Lakes. At this point you have hiked about 8kms and you have two more to go. This is the highest point of the Ten Lake hike and it is above 3000 meters. Then the trail plunges down into the valley of the lakes, an almost vertical drop.
Tenaya Lake or May Lake to Ten Lakes
This hike requires dropping one car at the Ten-Lake trailhead (T14) and driving on a second car to the May Lake trailhead or to Tenaya Lake (about 13kms east of the Ten-Lake trailhead, past the Porcupine Flat campground if you are driving east). Note that the May Lake road is usually closed until June so in the spring you most likely will need to start this hike at Tenaya Lake, bypassing May Lake.
The total distance is about 38 kms. There are a few places where it's easy to lose the trail.
If the road is open, the parking lot for May Lake is located 3 kms from Tioga Rd halfway between the Ten Lakes trailhead and Tuolumne Meadows, just west of Tenaya Lake. There is water at the very first restrooms on your left before you reach the shore of the lake.
The trail from May Lake reaches the Ten Lake area after circling around Mt Hoffmann and Toulomne Peak. Three steep climbs (three passes) are involved. The main attractions are the views from these passes (the third one is the classic ten-lake view) and the lakes themselves. The landscape changes dramatically between one pass and the next one. The price you pay is a long, tough hike because you go up and down three times, and the last one (if you go from May Lake towards the Ten Lakes) is the steepest. I doubt there are actually ten lakes: you only see four from the top of the last pass. Even if you add the two Grant lakes (which are on the other side of the ridge), you don't get ten.
May Lake to Ten Lakes to Grant Lakes back to May LakeIf you don't mind cross-country hiking, you can also return to May Lake by taking the detour to Grant Lake (a trail, although not well maintained). From the first lake head east to the second one (a creek connects the two). Head south climbing the ridge and keep heading south or, whenever you can, southeast. You should eventually connect with the east to west creek that comes down from the lakes behind Mt Hoffmann. To get back to May Lake you have to climb the ridge south and then west of Mt Hoffmann
Pictures of this hike