hikers on the dunes
In summer months, plan to explore the dunes in early morning or evening to avoid a dangerous 150 degree F sand surface or thunderstorms.

NPS/Scott Hansen

We want your visit to be safe and worry-free. Here are the basics you need to know as you plan your visit:

Hot Sand

Surface temperatures on the dunes may reach 150 degrees F on summer afternoons. To avoid heat exhaustion and burned feet, plan to hike the dunes in early morning or evening in summer months. Hot sand can blister or even cause second-degree burns on bare feet, the tops of feet (when wearing sandals), and any exposed skin that comes in contact with the hot sand. Wear closed-toe shoes when hiking on the sand. Take sunscreen, as skin burns easily at this high elevation (8,200 feet/2,499m at the visitor center). Remember your pet's feet are sensitive to burns, too.

Sand Collapse

Do not allow children to dig deep holes at the base of dunes. Rarely, dune slipfaces may collapse the hole, partially trapping a child.

Wind and Sand

While it's actually often calm here, winds can arise during storm fronts at any time of year. Spring is the main windy season, especially spring afternoons. Check weather forecasts in advance. While light breezes won't blow sand into the air, strong winds can create wind-blown sand that can be painful and or get into your eyes.

Lightning illuminates a dark sky
Lightning illuminates a dark sky.

NPS Photo


To avoid heat exhaustion and burned feet, plan to take your pet on the dunes only in early morning or evening in summer months. Surface temperatures often soar over 150 degrees F on summer afternoons, so shady mountain trails, including Montville/Mosca Pass Trails and Zapata Falls are better options. Pets must be on a leash and attended at all times to prevent encounters with wildlife. Never leave a pet in a car on a summer day; temperatures can reach 100+ degrees within minutes.

High Elevation

The visitor center and campground areas are about 8,200 feet (2,499m) above sea level. The highest elevation in the park and preserve is 13,604 feet (4,146m). Some people experience headaches, dehydration, fatigue, sleeplessness, rapid heartbeat, and shortness of breath at higher altitudes. Drink plenty of liquids, avoid alcohol and caffeine, and move slowly until your body acclimates over a day or two.


The dunes, mountains, and grasslands are subject to lightning strikes, especially on summer afternoons. When you see storm clouds forming or hear thunder, seek shelter in a building or in your vehicle. Use a lightning app to track the proximity of each strike. Wait at least 30 minutes after the last strike in the area before returning outdoors.

Water Quality

The water in the park is clean mountain snowmelt, but surface water may contain bacteria such as giardia. Backcountry hikers in the Rocky Mountains should treat any surface water by filtering or boiling.

A Mountain lion leaps through snow.
Mountain lions can jump great distances using their powerful legs.

NPS Photo

Mountain Lions

While mountain lions are very secretive and only rarely observed, their presence here is obvious from their tracks that are commonly seen in the foothills and edges of the dunes along Medano Creek. They are primarily nocturnal in the warmer months.

There have been no reported mountain lion attacks at Great Sand Dunes, but it's wise to stay alert when walking in their habitat. Always hike together as a group; children should not run ahead. A hiking stick is a useful tool for lion defense.

If you see a lion close to you:
1) Make noise
2) Stay calm and face the lion
3) Pick up/protect children
4) Stop and back away slowly. Running or quick movements can cause a lion to chase or attack.
5) Appear larger in any way; raise your arms or spread out a jacket.
6) Talk firmly and quietly.
7) Fight back if attacked. Throw stones, branches, or whatever you can grab.

Three black bears graze on green grass.
Despite their name, black bears can be black, brown, cinnamon, or even blonde in coloration.

NPS Photo

Black Bears

Black bears live in the foothills and mountains just above the dunes, but rarely visit the dunes. Despite their name, black bears can be black, brown, cinnamon, or even blonde in coloration. They are generally secretive and avoid humans. The most common safety problem is when campers or picnickers leave food out, inviting a bear into their site.

Never leave scented items or coolers unattended. This may result in your cooler being confiscated and a ticket resulting in a monetary fine. It could also endanger you and other campers by having a hungry bear in your site when you return. Use the bear lockers provided in Piñon Flats Campground, and/or store scented items in a vehicle with the windows rolled up.

Below is a checklist of how to respond if threatened by a black bear; keep in mind this is for black bears; and safety measures for grizzly bears (not in Colorado) may be quite different. Female bears protecting their cubs are the most unpredictable.

If you find yourself near a black bear:
1) Stay calm; if you get excited, the bear may get excited!
2) Stop. Avoid direct eye contact.
3) Slowly leave. Running or sudden movement may threaten a bear.
4) Speak softly to the bear to alert it to your presence. Do not yell.
5) Fight back, if attacked (use rocks, sticks, flashlight, bare hands).

Wood tick stands on a human finger.
Wood ticks (Dermacentor andersoni) attack humans, elk, and other mammals in search of a blood meal.

NPS Photo


The park has a relatively short 4-to-6-week mosquito season. In dry years, there may be few mosquitos, but in wet years, there can be very high numbers. As Medano Creek gets low and warm in the second week of June, mosquitos emerge in large numbers. Move away from vegetation, upstream, and on the far side of the creek to avoid the worst of the mosquitoes: they don't like open sand but prefer to be near shady bushes and trees.

Tiny biting gnats ("no-see-ums") are out in late spring and early summer. Their bites can cause itchy, red welts, but they are not known to carry disease.

Ticks are out in April through July in the forests surrounding the dunes. There are no ticks in the dunes. When hiking in forested or grassy areas during tick season, wear tick repellant on your clothing, and long pants with cuffs tucked into your socks to help prevent tick bites. If a tick attaches to you, use the CDC's Tick Removal Guidelines, and check for signs of tick-related illness.

Black widow spiders do exist throughout North America's woodlands and grasslands, but they are secretive and uncommon in the park. Do not reach under logs, rocks, or hidden crevices.


Venomous snakes have never been seen in this high-elevation park. Only harmless, non-venomous snakes and lizards live in the park and preserve. Rattlesnakes are occasionally seen in lower elevations of the San Luis Valley, primarily in rocky areas.

Deer, Elk, Pronghorn, and Small Mammals

Deer, pronghorn, and elk are often seen in the park and on park roads. Be alert and drive slowly, especially at night, to avoid hitting one of these animals.

Never feed or approach wild animals, including deer, birds, chipmunks, and ground squirrels. Deer may kick, and small rodents may bite. Nature provides plentiful food for wild animals, and they need the nutrients provided by wild food to remain healthy. Some wild animals carry diseases which can be transmitted to humans.

Deer mice are common rodents in the western U.S. whose droppings and urine may carry hantavirus, a potentially fatal illness. While there is virtually no risk of hantavirus from being in the open outdoors, entering enclosed spaces or digging in holes where deer mice are active can be potentially hazardous.

Last updated: June 17, 2024

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Contact Info

Mailing Address:

Visitor Center
11999 State Highway 150

Mosca, CO 81146


In the event of a medical emergency, missing person, or fire: Call 911. For non-emergencies (non-life-threatening situations): Call (719) 589-5807.

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