A stress-free camping trip requires a certain amount of forethought. Reserving a campsite, packing the right gear, and mapping out the best routes to and from your campground can help a trip go smoothly and give you something to look forward to in the weeks, even months, before your escape to the great outdoors. Sometimes, though, the camping bug bites on a whim. While securing a last-minute campsite can be more challenging than unearthing your sleeping bag, particularly during peak season or in popular wilderness areas, there’s no need to get discouraged if everything seems to be reserved already. Consider these tips next time you need a spur-of-the-moment site to hang your tent, so to speak.

Take your chances on a first-come, first-served site.

First-come, first-served campsites are no guarantee, but they do offer a glimmer of hope when all other campsites are turning up booked. Many major national parks have a limited number of reservation-free sites: Yosemite’s Camp 4 operates on a first-come, first-served basis year-round. Yellowstone’s Indian Creek Campground is available to last-minute campers between June and September. The Grand Canyon’s Desert View Campground is an option from mid-April to mid-October. Big Bend, Rocky Mountain, Crater Lake, and other national parks with serious name recognition also reserve a modest number of first-come, first-served sites.

A safer bet may be to consider less packed national parks, as well as state parks and other wilderness areas, that also operate on a no-reservations basis. California’s Pinnacles National Park, a couple of hours east of Big Sur, holds several first-come, first-served walk-up campsites for more spontaneous visitors. The same goes for the Stanley Lake Campground in Idaho’s Sawtooth National Forest, the Eagle River Campground in Alaska’s Chugach State Park, and others. Check out your options on Recreation.gov if you have your heart set on overnighting in a national park, and look to ReserveAmerica for the skinny on other protected spaces.

Whether you take a shot at a preeminently popular campground or hedge your bets on a site that rarely turns campers away, remember that even first-come, first-served sites require some preparation to secure. Call your park of choice in advance to learn more about which days fill up the quickest, and arrive early when you finally throw your hat into the ring. First thing in the morning is recommended. After all, they are called first-come, first-served campsites.

Keep your eye on cancellations.

Monitor Recreation.gov and ReserveAmerica closely, and you may luck into a cancellation. Social media, such as a park’s Facebook page or dedicated groups, may point you in the right direction, as well. Yet there are also resources designed specifically to help you secure sites that others gave up at the last minute. Campnab, for example, tracks availability in the campsite of your choosing, scanning for cancellations and sending you a text if a site opens up.

It’s not a free service, however. Pricing works one of two ways: pay-per-use scans that cost between $10 and $20 or monthly memberships that cost between $10 and $50. Campsite Assist operates much the same way and also charges a fee for every continuous scan, which can vary in frequency from every three to 33 minutes, depending on your selected fee, while UpCamp is free to download from the Apple Store and similarly notifies you of cancellations.

Try your luck with a backcountry permit.

Unlike car campers, backcountry campers have to work for their sites. That usually means hiking in rather than driving up. Because of this, and the fact that the backcountry does not come with amenities, permits are often easier to secure than spots at cushier campgrounds. Nonetheless, many need to be arranged at least 10 days out, and coveted backcountry areas can still fill up far in advance. The good news is that many parks and wilderness areas also offer a limited number of first-come, first-served permits each day. If you’re willing to wait in line outside of a backcountry office, try to get there before it opens to increase your chances of snagging one of the allotted permits or swooping in on a last-minute cancellation. Online applications often allow you to submit back-up dates and locations, as well, if you have some flexibility as to the when and where of your spontaneous trip.

Think outside the National Park System.

National parks come to mind first when we think of the United States’ finest public land. In fact, they only represent a fraction of the country’s 640 million acres of federally and state-protected land. National forests, wildlife refuges, conservation areas, monuments, trails, recreation areas, seashores and lakeshores, and other designations make up the rest, including some 245 million acres of land overseen by the Bureau of Land Management (BLM).

BLM lands are like the Wild West of camping given the relatively few crowds and rules typically enforced. It’s often free to camp on BLM land though fees may be required. You may need a permit for larger campsites, but BLM land is predominantly first-come, first-served. And backcountry or dispersed camping, which occurs outside of a designated campground, is common. Check the BLM website to discover options that rarely disappoint, like the Cottonwood Recreation Site near Joshua Tree, Hatch Point Campground or Canyon Rims Recreation Area in Moab, and Yakima River Canyon Campgrounds in Washington state.

Also worth keeping in mind is the United States Forest Service (USFS). There are 154 national forests across the country, many of which have campgrounds that consistently get passed over in favor of state or national parks. Campsites here generally operate similarly to those run by the BLM, with plenty of free and dispersed camping options. ReserveAmerica is a helpful resource for discovering national forest sites near you, and the Public Lands Interpretive Association map has information on both BLM and USFS options.

Pitch your tent on private land.

Another approach to last-minute camping is to ditch public lands altogether. Around half of the nation’s campgrounds are located on private land, and there are a handful of apps and websites to help you narrow down your search. The first place you check should be Go Camping America, which bills itself as one of the most comprehensive online databases for privately owned campgrounds and is operated by the National Association of RV Parks and Campgrounds. Hipcamp has its own database of private campsites, from spots to pitch your tent to places to hook up an RV to cabins for rent. If you strike out on both, you may find what you’re looking for at The Dyrt PRO, for a $29.99 annual fee, or Pitchup, a free listing service.

Consider a weekday escape.

Weekends, especially during peak season, are not always forgiving to planning-averse campers. It’s like trying to get a table at a trendy restaurant on a Saturday night. Enter the weekday reservation. Much as your chances of squeezing into that hip new Italian spot skyrocket on a Tuesday night, campsite availability is more widely available during the week, holidays notwithstanding. Centering your trip around less desirable days may mean playing hooky, depending on your schedule — but if ever there was a good reason to call out of work, it’s answering the much more enticing call of the wild.