Know-how
Most trips that go wrong were decided at the kitchen table, not on the trail. An hour of planning buys back the day.
Planning an overland trip is four questions. Can we drive it? Who manages the ground and what do they require? What do we need to carry between services? And who will notice if we do not come back?
The agencies that manage the land publish most of the answers, and the National Park Service publishes a good process for the last one. This guide sets out how to find each of them, and what not to trust.
The Park Service puts the first question plainly: know your limits, your skills and your experience. A route is within reach when the vehicle, the driver and the group are all comfortable with the hardest thing on it, not the average thing.
Read the agency's own description of the road rather than a video of someone driving it. Our route guides carry only what the managing agency publishes: the length, the high point, the surface, the season and the vehicle it says you need. Where an agency says high clearance, or four-wheel drive, or that trailers are unsuited, that is the specification.
Then plan a way out. The Park Service asks travellers to make a backup plan, and adds the sentence that matters most: "If a safety concern impacts your activity, consider turning around instead of pushing ahead." Decide at the table which junctions are your bail-out points, so you are not deciding it while tired.
Every rule that applies to you comes from whoever owns the dirt: a national forest, a Bureau of Land Management field office, a park, a refuge, a state agency, or a private landowner. Our public land map shows you which, and a click gives the managing unit by name.
Once you know the office, its own page is where the requirements live: permits, reservations, seasonal gates, stay limits, and whether the road you want is on the motor vehicle use map at all. The Park Service directs people to Recreation.gov for reservations and is explicit that a trip plan "is NOT a substitute for required activity permits".
Check the three things that change with the season and cannot be planned around a week in advance: fire restrictions, road status, and any permit quota. Know the page each one is posted on so you can look the morning you leave.
What to look up before a trip, by name
Work in range, not in miles. Take the vehicle's honest range on the worst surface you will drive, then plan to refuel at two thirds of it. The Department of Energy's own list of what lowers fuel economy is the reason for that margin: a roof load adds drag, extra weight and towing cost economy, hilly or unpaved roads reduce it, and simply engaging four-wheel drive "makes the engine work harder and increases transfer case and differential losses".
Water is arithmetic too, and the agencies publish the figure: at least a gallon per person per day in desert heat, more if you will hike, plus cooking and a full extra day. See our water guide for how to store and treat it.
Then write down where the last fuel is, where the last water is and where the last cell signal was, and treat each as a decision point rather than a landmark.
Use the National Weather Service point forecast for where you are going, but understand what you are reading. The forecast grid is 2.5 kilometres square, and the Weather Service itself warns that a grid box in the mountains can span three or four thousand feet of elevation, so "the forecast is for the grid box, and not necessarily for the mountain summit".
Two products should change a plan outright. A Flash Flood Warning means a flash flood is imminent or occurring, and the Weather Service notes you can experience one in an area not receiving rain at all: if you are in a flood-prone area, move to high ground. A Red Flag Warning means critical fire weather is happening or about to, which is when restrictions tighten and when a spark matters most.
The corresponding watches, Flood Watch and Fire Weather Watch, mean conditions are favourable but nothing is happening yet. That is your cue to move a camp off a wash, not to cancel.
Do not skipNever drive into flood water. Six inches of moving water knocks down an adult, twelve inches carries away most cars, two feet carries away trucks and SUVs, and over half of flood drownings involve a vehicle. Do not drive around a barrier: the road under the water may be gone.
A trip plan is a written note of where you are going, what you are doing and when you will be back, left with someone who is not coming. The Park Service is precise about it, including the part people get wrong: do not leave it with the park, because they will not accept it.
Give your trusted contact the route, the vehicle, who is in it, your expected return time, and what to do if you are late: try your number, then contact the authorities and pass on the plan. Then stick to the plan, because search and rescue is "substantially impeded" when a visitor deviates from it. If you change the route, tell them.
Set the return time later than you expect and the panic time later still, so an extra hour taking photographs does not start a search. Then check in when you get out, every time, or the system stops being believed.
Travelling with a second vehicle changes the arithmetic of everything: a stuck vehicle has a recovery, a failed vehicle has a tow, an injury has a driver. It also slows you down and doubles the number of opinions at each junction.
Travelling alone is entirely reasonable on roads within your ability, with the margins widened: more water, more fuel, a satellite messenger, and a trip plan that someone is actually watching. What it is not is a good place to try the hardest thing you have ever driven.
Whichever you choose, the Park Service's reminder about phones applies: your cell phone is not a substitute for the essentials, you may have no service, and the battery may not last the trip. Carry a paper map as well.
The advice from the Park Service, the Weather Service and the desert parks agrees: stay with the vehicle. It is shelter, it is visible from the air, and it holds your water. Moving makes you harder to find, and the Park Service says to move only if there is an immediate threat to life.
Make yourself findable. Raise the hood, tie something bright to the antenna, and if you are in Death Valley's situation, mark the road with a large X. Then ration water and wait for the cool part of the day before doing anything strenuous.
Search and rescue takes hours or days depending on the weather and the resources available. That is the real reason the trip plan and the return time matter: they are what starts the clock.
Reading a guide is not training. A course in trip planning, navigation or expedition driving gets you further than another set of tyres, and the instructors in the directory teach exactly this.
The cheapest practice is a shakedown: a night close to home with the vehicle loaded as it would be, cooking the meal you would cook. Everything you forgot will announce itself within four hours of home rather than four hours from a paved road.
Where you are going, the route, the vehicle, who is with you, and when you will be back, left with a trusted contact who is not on the trip. Ask them to call the authorities and share it if you are late. Do not leave it with the park: the Park Service says they will not accept it.
From the agency that manages the ground. On national forest land the motor vehicle use map is the legal record; the Bureau of Land Management and the parks publish their own travel maps. Our public land map shows which agency manages any point you click.
Refuel at about two thirds of your real range on the worst surface of the trip. A roof load, extra weight, unpaved roads and simply using four-wheel drive all reduce fuel economy, so a highway figure will mislead you.
Read it knowing the grid is 2.5 kilometres square. The Weather Service warns that in the mountains that box can span 3,000 to 4,000 feet of elevation, so a point forecast is not the summit forecast.
No. Six inches of moving water can knock down an adult, twelve inches can carry away most cars and two feet can carry away an SUV or a truck. Turn around, and never drive around a barrier.
Reviewed September 19, 2026. Conditions, closures and rules change; check with the managing agency before you travel.