This is the big one - more than 40 miles and going up to 10,000 ft, with I guess at least 10,000 ft. of climbing. It's a long day, but what a walk. Park in the Village in the valley. Take the Nevada Fall trail all the way to the top (it splits over the last mile or two, doesn't matter which you take, they are both uphill.) Check out the footbridge over the top of Nevada Fall, before going on up the Little Yosemite valley to the Bunnell Cascade which separates the Little Yosemite from Echo Valley. All pretty easy walking on a good trail, but steady climbing all the same. Near Echo Valley you can fork right to coninue up to Merced Lake and a popular campground if you wish, then return to the juncion and take the other fork over the low ridge (good views of Echo Valley from the top) and down to John Muir Creek. After crossing the creek, turn right on the Tenaya Lake trail for another 3 miles or so, then make a left on the narrow Clouds Rest trail. You might have trouble following this trail, especially in June as you are likely to hit the snow line - but just keep climbing, it's pretty obvious where the top is. When you finally make it to the top of Clouds Rest and come out on the bare rock at the north east end, you will have to scramble over the rocks a bit along the (short) top. At the south west end of the summit of Clouds Rest, take a breather and enjoy looking down on Half Dome, with the Quarter Domes in front of it and Glacier Point behind. Across Tenaya canyon on your right you can look down on North Dome, whilst looking straight down the Yosemite Valley, past Half Dome, you can see below you the summit of El Capitan. When you've taken all this in, follow the well-marked trail down the south west side of Clouds Rest to the Little Yosemite Valley. Cross Nevada Fall on the footbridge to Panorama Cliff, then take the long climb up to the Illouette trail. Right on the Illouette trail to Glacier Point (the refreshment stall will be closed by this time!) and take Four-Mile trail down to the Yosemite Valley again. This I have measured, and neglecting diversions, you've topped 40 miles in the day.