Kevin, The Sierras go from Kennedy Meadows in the South to around Lake Tahoe in the North. If you are still looking at May/June, there will likely be a lot of snow the entire way, possibly total coverage due to the heavy snow this year. If you come in to Yosemite from the west, Yosemite village is only around 4,500 feet and will probably be clear of snow by May. The falls are the best from late April to mid June. You can explore in that area.
If you mean how is the 300 miles of the PCT south of Yosemite… These are the highest mountains in the Sierra and will be completely covered by snow in May and probably June this year. If you would like to do a 300 mile section of the PCT in May/June, the best area would be Big Bear Lake to Walker Pass. That is about 300-400 miles. Robocop
Robocop