To limit crowds at Yosemite National Park, the National Park Service will implement a day-use reservation system this summer.

Starting May 21, park visitors — including annual and lifetime pass holders — will be required to make day-use reservations, valid for one vehicle for three days. Depending on the evolving COVID-19 situation, visitor capacity will range from 50 to 90 percent of the park’s usual visitor numbers.

Cicely Muldoon, the park’s superintendent, said at a meeting of local government and community leaders, “The basic plan is to protect human health and safety and provide as much access as we can. We think these numbers will allow people to enjoy the park safely.”

The system will be familiar to anyone who visited the park last summer, when reservations were put in place from June to October. This summer, however, over 580 campground sites will be open, compared to only 247 last year. In 2021, the day-use reservation system will be in place from May 21 to September 30.

The NPS wrote in a statement, “The temporary day-use reservation system will allow the park to manage visitation levels to reduce risks associated with exposure to COVID-19.”

Reservations will go live on recreation.gov at 8:00 AM PT on April 21. Overnight guests staying in a hotel or NPS-managed campground will not need a separate day-use reservation.