My wife and I visited Yosemite last June. We decided on the trip to late to make reservations in the park. To try to get a jump on the crowds, we entered the park each day before or at dawn, at the latest. We had no trouble with that, and obviously got the best light, by doing that. A couple of times, we saw entrance areas to the park during our various rounds throughout the day, and the lines were monumental. In those lines do not move quickly, because you have only one traffic lane in the entrances we saw. So particularly if you are not staying in the park, I would counsel getting in as early as possible.

From a practical side, don't forget to pack enough warm clothes, because the higher elevations and the snow pack from this past winter and the ongoing snow storms will drastically reduce the ambient temperatures, and they will drop sharply as sunset approaches!

I found out the hard way many years ago, when we attended a horse show in the mountains of NH in August. We hadn't planned on staying for the evening session so out summer clothes were no match for the evening mountain temperatures, but fortunately I had extra coats, jackets and blankets in my van to keep everyone warm that night.

But on a trip to Yellowstone one year the week after Labor Day, I didn't fare as well because I was advised to leave my winter jacket at home. I absolutely froze the whole week we camped out!

My first visit to Yosemite was in 1951, and wow, has it changed over the years. There was a huge rock fall that changed the Happy Isles are leading up to Vernal Falls so some of the buildings are no longer there.

Personally, I would head up to Tuolumne Meadows for some really great back country views. Also, if you want to see what San Francisco destroyed in order for water and power, visit Hetchy Hetchy valley. Although it is full of water, it is easy to image what it could have been. Ansel Adams remarked it was one of nature's best creations.

The Ahwahnee Hotel (now the Majestic Yosemite Hotel) has a great restaurant and you don't have to stay in the hotel to eat there. You need reservations to stay in the hotel, but it is one of the better places to spend a couple of nights that I have enjoyed. My father was actually stationed in this hotel right after the start of WWII as it was used as a Navy recovery hospital.

If you are staying in the valley floor area, you might try taking the morning bus to Glacier Point. Fabulous panoramic views up the Merced River (Yosemite, Vernal and Nevada falls), Half Dome, El Capitan, etc,. Four Mile (actually 4.7) Mile trail takes you back to the valley floor and is a good, if not very tiring downhill, hike (you need really good fitting boots and make sure your toenails are cut short).

On the way out of Yosemite you'll be taking Hwy 41 through Wawona. This is the home of some of the largest trees anywhere, the Sequoia. There is a hotel with a decent restaurant at this location.

The Sierras have received record snow falls this year (they just received a 2 foot 'dusting' this last week) and there may be some road closures (in June??, yes, June). Pay attention to weather reports just prior to your trip. If there were heavy May/June rains, the snowpack may melt quickly and the valley has flooded. 1997 was a terrible flood and there was even flooding earlier this year.

Good luck, make sure you have charged batteries and take a million images.

Try to get a copy of Photographing Yosemite - Digital Field Guide, by Lewis Kemper. It is available on Amazon for aout $20. Kemper identifys all of the great shooting locations in Yosemite with detailed maps, commentary and many excellent photos. I spent about a day planning our recent visit to Yosemite with this book. It enabled me to use my limited time there to best advantage and I was able to get some really great photos (if I do say so myself). Enjoy your visit -- there is no other place in the world quite like Yosemite.

Tioga Road may very well be closed until mid summer. Lots of snow this year. The road to Glacier Point has been closed for a while. Getting into the valley before sunrise and staying to after sunset will yield some wonderful lighting. Look for shots in unexpected places. Park and ride the free shuttle buses. Parking a private vehicle is a bear, no pun attended. Don't speed, the rangers love to ticket.

This site will give updates to road conditions.
https://www.nps.gov/yose/planyourvisit/conditions.htm

From a "local" Point of view, I live near Reno, NV, and this year was an EPIC snow year and it is still snowing at high elevation. The great news is that the falls will be flowing very well and fast. The serious caution news is: The water will be running very fast and COLD. Also, depending on the temperatures of the later Spring months, the valleys are susceptible for flooding, In Yosemite that translates into:

Valley and High Country Campgrounds being flooded or closed or opening later into the season.
Bridalveil Creek campground (off Glacier Point Rd) and the High Yosemite Falls off Tioga Rd. may open late.

Be sure to check the resources Steve has mentioned. Similar cautions are valid for Sequoia and King's Canyon. Lots of Snow means lots of water in places that haven't seen very much in 5 years.
Tioga Pass (entrance from US 395 from Reno may be opening later than usual in the year.

Enjoy your trip. It will be a spectacular year, and the wildflowers should give us another Super bloom,
C