(Stacker) —  Jam-packed parking lots, gridlocked roads, bustling crosswalks—these aren’t scenes from New York City or Los Angeles but from some of the country’s most popular national parks.

According to reports from the National Park Service, destinations like Arches and Rocky Mountain National Parks have seen record visitation numbers in recent years, resulting in unprecedented overcrowding.

Fortunately, the National Park Service is already taking steps to save our national parks from being visited to death. Most notably, several of the nation’s most-visited parks have implemented permit systems, which require visitors to make advance reservations to enter. This helps park officials manage traffic flow and prevents parks from becoming overwhelmed by numbers they can’t accommodate.

These permit systems aren’t without their critics, as some have said this measure can make it much more difficult for visitors to experience the national parks. But it’s important to note that most of these permit systems only apply during peak visitation season (namely, the summer months), so you can still enjoy a spontaneous national park trip during much of the rest of the year—at least for now.

Using information from Outside and the National Park Service, Stacker compiled a list of six national parks that will require entry permits in 2024, excluding parks that only require permits for specific landmarks. Don’t forget that permit reservation fees won’t cover national park entrance fees, typically charged when you enter the park.

Read on to learn where you’ll need a permit—and how to get one—this year.

Yosemite National Park

Yosemite first instituted its timed entry system in 2020 to limit visitor numbers during the COVID-19 pandemic, but even when cases began to subside, Yosemite kept the permit system around to alleviate longstanding overcrowding issues. After removing the system for one year in 2023, the park has brought back the entry permit requirement for 2024.

Permits have been required to enter the park on weekends and holidays since April 13 and will be required every day from July 1 through Aug. 16. From Aug. 17 through Oct. 27, permits will only be required on weekends and holidays again. Most permits were released on Jan. 5 this year, but for last-minute trip planners, further permits can be reserved seven days before your expected arrival date.

Inside Yosemite, you can marvel at the views of El Capitan and Half Dome or hike one of the park’s many scenic trails, all while enjoying the benefits of fewer crowds.

Mount Rainier National Park

Mount Rainier National Park has seen a 40% uptick in visitor numbers over the past 10 years. To preserve the park’s delicate environment and offer an improved visitor experience, Mount Rainier will require permits to enter both the Paradise and Sunrise Corridors during peak visitation days in 2024.

Reservations are needed for Paradise Corridor from May 24 to Sept. 2, while Sunrise Corridor requires entry permits from July 4 to Sept. 2. Both the Sunrise and Paradise areas offer their own unique attractions—Sunrise features stunning views of Mount Rainier and the Cascade Range, while Paradise hosts the park’s main visitor center and abundant wildflower meadows.

You’ll need to reserve two separate permits if you want to visit both spots this summer, but if the timed entry system works according to plan, you hopefully won’t have to share the park with too many other tourists.

Arches National Park

Anyone who’s visited Arches National Park in recent years won’t be surprised to find it on this list. After experiencing significant overcrowding for more than a decade, Arches implemented a timed entry program in 2022. Now in its third year, the system continues to evolve to accommodate visitors and provide the best experience possible.

Entry permits are released in monthly blocks three months before each month (for example, permits for September visits are released on June 1). A small number of additional permits are released one day ahead of time, which allows for a certain degree of spontaneity in planning your trip, though these permits may get snapped up quickly.

Explore the park’s namesake sandstone foundations and learn more about the unique combination of elements that led to their creation, keeping an eye out for wildlife like bighorn sheep that have made a home in this desert landscape.

Rocky Mountain National Park

From May 24 through Oct. 20, every vehicle that enters Rocky Mountain National Park will need a timed entry permit. There are two different types of permits: Timed Entry+, which includes popular destinations along Bear Lake Road, and the regular Timed Entry option, which excludes Bear Lake access. You’ll have to pay close attention as you reserve your permit.

It might seem onerous to plan your trip activities so far in advance. But considering you’re helping preserve the park’s gorgeous, one-of-a-kind alpine landscapes using the timed entry system, a little extra legwork doesn’t seem so bad. When hiking to Lake Haiyaha or soaking up the sights at Moraine Park, your permit will be all the more worth it.

Carlsbad Caverns National Park

As most of its attractions are deep underground, Carlsbad Caverns is slightly different from the other parks on this list. Carlsbad requires timed entry permits 362 days a year, from January through December. The only exceptions are Thanksgiving, Christmas, and New Year’s, when the park is closed to the public.

But park officials have long restricted entry to Carlsbad Caverns, reducing strain on the sprawling cave system and karst formations. You can view the caves on ranger-guided tours, which depart from the visitor center several times a day, or you can hike down alone.

Glacier National Park

In the summer of 2024, Glacier National Park will require visitors to have a vehicle reservation to access Going-to-the-Sun Road, the North Fork area, and Many Glacier valley. Entry to these areas will be restricted between 6 a.m. and 3 p.m. from May 24 through Sept. 8, exact start dates vary with each location.

If you have your trip dates set ahead of time, try to snag one of the reservations available 120 days (four months) before your trip. If you’re unsure, log in to recreation.gov early the day before your arrival to book a permit.

Those reservations will grant you access to some of the most spectacular natural landscapes in the western U.S. Going-to-the-Sun Road winds past snowy Rocky Mountain peaks, while Many Glacier valley features dramatic alpine scenery that draws hikers from all over the world.

Story editing by Carren Jao. Copy editing by Paris Close. Photo selection by Clarese Moller.