It depends on when you are going -- by later in March, much of the snow melts on the valley floor. We've been there in early March where we had to shovel a little snow in order to store stuff under the trailer. Just in case, maybe bring a small shovel. I don't think an ordinary snow shovel is either necessary or adequate -- the old snow tends to be clumpy and icy, and a regular garden shovel might do a better job of penetrating the pile.
If you are there in a cold snap, try to take the trail up toward the top of Yosemite Falls -- the spray freezes on the cliff walls at night and then breaks off and thunders down in the morning. Very exciting, and fortunately not onto the trail.
2012 Fun Finder X-139 "Boondock Style" (axle-flipped and extra insulation)
2013 Toyota Tacoma Off-Road (semi-beefy tires and components)
Our trips -- pix and textAbout our trailer"A journey of a thousand miles begins with a single list."