Mountain Road Trips: Altitude Sickness, Sudden Storms and Cold Nights

Mountain roads deliver some of the best views on any road trip.

They also bring conditions that many drivers from lower ground do not expect.

The air is thinner, the weather changes fast and nights can turn cold even in summer.

None of this should keep you away from the high country.

It just means planning a little differently.

This guide covers altitude, weather and cold, using guidance from the National Park Service and the National Weather Service.

Altitude can affect you even on an easy drive

Many people think altitude sickness only affects climbers.

That is not the case.

The Yellowstone safety page notes that most of the park lies more than a mile above sea level.

It warns that visitors can develop Acute Mountain Sickness on an easy hike or even a leisurely drive.

Many scenic highways and mountain passes climb to similar heights or higher.

If you live near sea level, your body may notice the change within hours.

Know the warning signs

The NPS lists the symptoms commonly experienced by people visiting high altitudes.

  • Headache.
  • Increased breathing.
  • A rapid pulse.
  • Nausea or loss of appetite.
  • Lack of energy.
  • Dizziness.

The park calls these warning signs not to go any higher than you already are.

On a road trip, that may mean skipping the next high pass for now.

What to do if someone feels sick

The NPS guidance is direct.

If you or someone traveling with you has these symptoms, descend to lower elevations right away.

Spend at least a day at an elevation where you feel comfortable before climbing again.

A car makes descending easy, so use it.

Some signs mean the situation is serious.

  • Loss of balance or coordination.
  • Slurred speech.
  • An altered mental state.
  • Extreme shortness of breath.
  • A wet or rasping cough.
  • Blue skin.

The NPS warns these can signal severe altitude sickness, and the person's life may be in danger.

Go down immediately and get medical help.

Call 911 if you have cell service.

Plan the climb into your route

A few planning choices can make high elevation easier on everyone.

  • Avoid driving from sea level to a very high pass and hiking hard on the same day.
  • If possible, spend the first night at a moderate elevation.
  • Keep the first day at altitude light, with short walks and plenty of rest.
  • Know where the lower towns are along your route in case someone feels unwell.

If anyone in your group has a heart or lung condition, ask their doctor before the trip.

The doctor can advise whether high elevation is safe for them.

Mountain weather changes fast

A calm, sunny morning in the mountains does not promise a calm afternoon.

The NPS warns that calm mornings in Yellowstone can turn into fierce, stormy days.

Gusty winds are common in the afternoon, and rain and lightning often follow.

The park advises getting off ridges and open places when storms approach.

It notes that thick forests of equal height offer better protection from lightning than meadows.

For drivers, a few habits help.

  • Check the forecast for the highest point of your route, not just the town where you sleep.
  • Plan high viewpoints and short hikes for the morning.
  • Head back to the car when you hear thunder or see clouds building fast.
  • Slow down on wet, winding roads and leave extra room ahead.

Our guide on thunderstorms on a road trip explains where to shelter from lightning.

Winter can show up any time of year

High country follows its own calendar.

The NPS says Yellowstone can see winter-like weather any time of year.

Depending on elevation, summer nights can drop into the 20s with a light freeze.

That surprises many summer visitors who packed only shorts and sandals.

  • Pack a warm jacket, a hat and gloves for every person, even in July.
  • Bring rain gear, because cold and wet together are the real danger.
  • Keep a blanket in the car.
  • Check overnight lows before you book a campsite at high elevation.

Some mountain roads and passes close for snow outside summer.

Check park and road alerts before you count on a route.

Hypothermia is a year-round risk

Hypothermia is not only a winter problem.

The NPS warns that rain, wind, snow and cold water make it a year-round risk.

It notes that most hypothermia cases happen in air temperatures of 30 to 50°F.

Those are temperatures many people do not think of as dangerous.

The park gives simple steps to avoid it.

  • Stay dry and stay out of the wind.
  • Put on rain gear before you get wet.
  • Put on warm clothes before you start shivering.
  • Wear a hat and gloves to keep body heat in.

The NPS lists warning signs too.

Persistent or violent shivering is a clear sign that someone is close to hypothermia.

Other signs include slurred speech, clumsy hands, exhaustion, confusion and drowsiness.

If someone shows these signs, get them out of the wind and rain.

Remove wet clothing and replace it with dry layers.

Give warm drinks without alcohol.

A warm car with dry clothes inside can be a lifesaver here.

Get the car ready for the high country

Mountain driving asks more of your car than a flat interstate.

Long climbs work the engine, and long descents work the brakes.

Before you leave, the National Weather Service recommends making sure all fluid levels are full.

It also names the lights, heater and windshield wipers in its pre-trip checks.

Our pre-trip car check walks through each step.

On the road, a few habits help.

  • Fill the tank before long mountain stretches with few services.
  • Watch the temperature gauge on long climbs.
  • Check your owner's manual for how to use lower gears on long downhill grades.
  • Use pullouts to let faster traffic pass and to rest your brakes and your nerves.

Tell someone your route

Many mountain roads have long stretches without cell service.

The National Weather Service suggests letting someone know your route and timetable before cold-weather travel.

That habit is smart for any remote mountain drive.

Share where you plan to stop each night and when you expect to arrive.

Download offline maps before you lose signal, and carry a paper map as a backup.

A mountain road trip checklist

  • Altitude symptoms reviewed with everyone in the car.
  • Lower towns along the route noted in case someone feels sick.
  • Forecast checked for the highest point of the route.
  • Warm layers, hats, gloves and rain gear for every person.
  • A blanket and extra water in the car.
  • Fluids, lights, heater and wipers checked before leaving.
  • Gas tank filled before long remote stretches.
  • Route and timetable shared with someone at home.

The bottom line

The mountains reward drivers who respect them.

Watch for altitude symptoms and head lower if they appear.

Plan high points for the morning, pack for cold even in summer and stay dry.

With a ready car and a flexible plan, the high country is one of the best parts of any road trip.

Sources and Further Reading