Sponsored by The GMC AT4 Lineup

You’ve decided! Your next family trip/solo getaway/bucket list road trip is going to be a National Park. But once you’ve picked your park, you’ll need to lock in several other critical details to make the most of your precious time and gas tank.

If this is your first time planning a big National Parks vacation, or if you’re going farther afield than usual, here are a few things to iron out early on in your planning.

1. Reserve your lodging or campsite ASAP

If your goal is to stay in the park proper—which lets you avoid some of the park’s daily traffic delays—you’ll want to book your reservation 12 to 16 months in advance. Yeah, you read that right, that’s more than a year. Lodges in the parks tend to fill up quickly, and reservable campsites can go in a snap, too.

Most popular parks, like Yellowstone or Glacier National Park, open their reservations 12-13 months ahead of the next season. So, for example, Yellowstone typically opens the following year’s summer lodging reservations on May 1.

If you’re OK rolling the dice on lodging, some parks, like Joshua Tree and Olympic National Park, have non-reservable campsites that you can try to snag upon arrival. But know that people start lining up for these sites in the wee hours of the morning during the most popular seasons. Don’t expect to drive up to the busiest section of the park in the middle of the afternoon to a free campsite.

Missed the window on in-park accommodations? You can always call the lodge you’re interested in to check for cancellations, which might have freed up a room. Beyond that, check the surrounding park towns or go a little farther afield to find more lodging options. For example, visitors to Yosemite might enjoy staying in the Old Western town of Mariposa and the glamping abodes at AutoCamp.

2. Check the seasonal weather and openings

Since National Parks are all about being in the great outdoors—rain or shine—understanding what the weather could do during your visit is important. Sections of parks with especially high elevation—like Yosemite National Park, Rocky Mountain National Park, and Glacier National Park—remain closed due to icy/snowy patches well into the summer, limiting both car travel and hiking opportunities. On the other hand, Grand Canyon National Park can be almost unbearably hot in the middle of the summer, especially deeper in the canyon where temperatures are higher than at the rim.

Since you’re going to be outside so much, you’ll want to understand the kind of temperature and weather you’ll be facing. Of course, nobody can predict rain or shine six months in advance, but a little research goes a long way. Once you know your best weather window, you might decide to shift your trip dates, plan an alternate route due to closed roads, or stock up on cold-weather clothing if you decide to forge ahead into less-than-perfect conditions.

3. Book popular tours and apply for hiking permits in advance

Travelers often have dreamy visions of what their National Park trip will look like, say, whitewater rafting through the Grand Canyon's Colorado River or hiking up the steep crest of Yosemite's Half Dome.

But it’s not as simple as showing up with a spring in your step. Popular tours, like rafting the Colorado or taking a mule to the bottom of the Grand Canyon, can book up a year in advance. Waiting until the last minute means you could miss the boat (or the raft!) for that once-in-a-lifetime experience.

It’s a similar story for beloved trails, where parks sometimes limit the number of people who walk them every day in order to preserve the experience and keep the trail in good shape. Many of these permits are for backpacking trips only (meaning you plan to hike and carry gear with you to camp on the trail). For example, the Wonderland Trail, which circumvents Mount Rainier at Mount Rainier National Park, requires permits for backpackers, but day hikers can hike sections at their leisure. However, other areas, including Half Dome in Yosemite, require permits even for day hikers.

Permit systems are often done by lottery—you apply and hope your name gets drawn in advance. Even if that doesn’t happen, some areas may have walk-up permits available or additional daily lotteries. It depends on the park and the hike. So if there’s a hike you’ve always wanted to do in your National Park of choice, make sure to check whether permits are required and how to obtain them.

4. Figure out how you’re getting there

Unlike other popular vacation destinations, it’s not as simple as calling a cab at the airport to get to a National Park. Most National Parks are not exactly an easy commute from major metro areas. For example, Grand Canyon National Park is 3.5 hours from Arizona’s major airport, Sky Harbor, and 1.5 hours from Flagstaff, the nearest city. Uber’s not going to cut it.

You’ll either need to drive from home, rent a car near the airport, or book an inclusive tour that will not only get you from the airport to the park, but also everywhere you want to go within the park.

Keep in mind that most National Parks are massive—Yellowstone is more than 2 million acres, larger than the state of Delaware. They’re best explored with several days to drive and hike around, at minimum, and you could easily spend a few weeks going hiking, fishing, and exploring beyond the big-ticket sites. You’ll be able to reach most popular areas in parks with any reliable sedan (and occasionally tire chains if there’s snow and ice), but some parks, like Death Valley, Big Bend, and Badlands National Park have areas where a 4x4 will get you to some less-populated places.

5. Make a plan to download or buy maps and itineraries

The great thing about National Parks is that they put you up close and personal with America’s natural places. The not-so-great thing is that cell service—and therefore internet access—can be few and far between. And the last thing you want to happen is to be stuck on a mountain waving a cell phone around trying to figure out which direction leads back to your car.

Before your trip, make sure you have plenty of offline resources to get around. That might mean downloading offline Google Maps for navigation around the park or purchasing trail maps if you plan to hike the area.

Another pro tip: Download the NPS app, which allows you to access driving maps and resources, like cool self-guided audio tours, lists of what to do and see, and alerts about road closures.

6. Get your parks pass

If you’re just hitting one National Park this year, go ahead and pay the entrance fee on arrival. The vehicle fee to enter a single National Park is $30 and it’s good for two weeks.

But if you think you’ll visit more than one National Park this year—especially if chances are good that you’ll visit them more than two weeks apart—upgrading to the America the Beautiful Pass is well worth the price. At $80, the America the Beautiful Pass gets you into every National Park, national forests and grasslands, and Bureau of Land Management land in the United States for a year. It's even cheaper for seniors, and if you have a child in the fourth grade, you'll get the pass for the year for free. Military members and permanently disabled U.S. citizens or permanent residents also get the pass for free. Sometimes the pass can even speed up your wait time—if you have a pass already, you might get access to a kind of “express” lane when entering the park, since you won’t have to stop to pay.

They’re available online or by phone ahead of time via the National Park Service website.

7. Make a list of gear you need

Don’t make the rookie mistake of coming to a National Park without thoroughly assessing your gear. Do you have a warm layer like a puffy or fleece jacket? What about a rain jacket? If you plan to hike in a park known for inclement weather, rain pants can be a good investment, too. And if you plan to hike anything but the most smooth, flat trails, you’ll want to consider hiking shoes or boots.

There’s a phrase you should know, too: “Cotton kills.” It sounds dramatic, but it’s referring to the fact that when cotton gets wet, it tends to stay wet and cause heat loss. Instead, experienced hikers recommend wearing all synthetic or wool clothing, just in case you get stuck out longer than you expect. Both are better at wicking sweat, and wool regulates temperatures significantly better. Avoid cotton socks, too—they tend to cause blisters as sweat accumulates on a hike.

For campers, you’ll want the typical hiking gear, and you’ll want to make a thorough list of items that will keep you comfortable, from warm sleeping bags to comfy camp chairs. Getting geared up appropriately means you’ll avoid huddling in your tent at 5 p.m. because the sun went behind a mountain, and it got too cold.

You might like:

The Minimalist Camping Approach: 10 Items You Absolutely Don’t Need

Buy-It-for-Life Camping Gear, According to a Pro

Colleen Stinchcombe writes about outdoor recreation, health, and the environment. Her work has appeared in Outside, Sierra Magazine, and The Seattle Times, among others. When not on assignment or crouched over a laptop, she's likely hiking, biking, or curling up in any available sunbeam at her home near Seattle, WA.