Some Worthy Side Trips to Consider
If you're flexible with your travel to Yosemite, there are some side trips in the vicinity that'd be worth considering.
Devils Postpile National Monument: Long ago a part of Yosemite, the Postpile is a geologic and biological wonder in the Eastern Sierra. Located just about 35 miles south of Yosemite’s Tioga Pass Entrance, the western half of the 800-acre monument reveals the granitic underpinnings of the High Sierra, while the eastern half reflects the volcanics of the eastern Sierra. Indeed, the "postpile" was volcanic in creation.
The monument also is relatively biologically rich, located as it is at the convergence of 3-4 bioregions (eastern, western, southern Sierra, and possibly the northern Sierra). Not only is the valley that the monument sits in a migratory corridor for deer, but it also sees a fair amount of migratory birds and is a mixing point for eastern and western Sierra vegetation such as Red fir, sagebrush, and Great Basin juniper.
June Lake Loop: A scenic pocket between Yosemite and Devils Postpile, the this community is given over to outdoor recreation. Bordered to the west by the Ansel Adams Wilderness Area, June Lake is a good basecamp for excursions into the national forest, and even the national park beyond, if backpacking is your preferred method of travel. There also are some excellent dayhikes here, as well, and lakes for fishing.
Mono Lake: Once nearly drained dry by thirsty Californians, this lake that covers 70 square miles just east of Yosemite is a destination for millions of migratory and nesting birds, and a great spot to dip your paddle.