Is Yosemite Open?
Yes. The official NPS Yosemite website says you can enter the park, but you need a reservation even for day-use (unless you enter by foot, bicycle, or YARTS public transportation.)
But some employees are saying that this changes on March 1, (which is today) and starting March 1 you do not need a reservation to enter the park for day-use.
Our advice? Check the website before you go, and call for the latest information!
That, and ask the park to update its website while you are at it!