May in Yosemite in the perfect time to start chasing waterfalls. As the warmer weather begins to melt snow from higher elevations, even small creeks and streams are rushing with water. You will see many, unnamed waterfalls cascading down the Valley walls. And the big waterfalls, like Yosemite Falls and Bridalveil Falls are pouring over their cliff. There are many trails that are starting to be cleared from snow in May, making hiking to the waterfalls accessible. Be careful when hiking to these waterfalls, however, stay on the trail and never swim in the pool above a waterfall.
The roads in the Valley are cleared from snow in May, so biking through the Valley is a great option. Bikes are available for rent at Curry Village, or at the Yosemite Valley Lodge. With 12 miles of paved and flat bike paths, biking is a great way to see the Valley.