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Lava River Cave, Flagstaff

#2 of 9 in Wildlife in Flagstaff
Cave · Hidden Gem · Nature / Park
Lava River Cave is a lava tube in northern Arizona's Coconino National Forest. At approximately 0.75-mile (1.21 km) long, it is the longest cave of its kind known in Arizona. The cave was discovered by some lumbermen in 1915 and has historically been referred to as "Government Cave" due to its location on the eastern edge of Government Prairie and southeast of Government Peak. Today, Lava River Cave is freely accessible to the general public.

Geologists believe the cave was formed sometime between 650,000 and 700,000 years ago when molten lava erupted from a volcanic vent in nearby Hart Prairie. The top, sides and bottom of the flow cooled and solidified, while lava in the middle flowed out, leaving a hollow space to form the cave. Examples of both ʻAʻā and Pāhoehoe basaltic lava can be seen in the cave.

The cave is mostly dry, but due to the temperature change, there is a lot of condensation on the walls, ceiling and floor near the entrance, which makes it slippery. Temperatures inside are around 40 °F (5 °C) during the summer, and it is not uncommon for some of the rocks to be covered with ice. The cave can range in height from 30 feet (9.1 m) to only 2 to 3 feet (0.61 to 0.91 m), although the latter only at a side passage that rejoins the main tunnel. There are no light sources inside. It is recommended visitors have sturdy hiking boots, warm clothing, and multiple sources of light.

Litter and graffiti have been problems since the late 1960s. A major restoration effort was organized in May 1991. Almost all the litter was packed out and much of the graffiti removed at that time. Dogs should not be taken in the cave since there are only limited and very slow biological processes to render their urine and feces unobjectionable.

The entrance to the cave is around 14 miles (23 km) west of Flagstaff, Arizona. Being in Coconino National Forest, the cave is managed by the United States Forest Service. While the cave is open year-round, the dirt roads which lead there may be impassable to cars in winter months or during wet weather conditions. There are no entrance or use fees.
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Lava River Cave reviews

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TripAdvisor traveler rating 4.5
457 reviews
  • Absolutely one of the best days of my life so let me explain the whole thing before you go watch football since im very young i was obviously scared (were talking under 13 but not saying age) but I....  more »
  • I loved this hike but it can make you feel very vulnerable. I would highly recommend a head lamp, layered clothing to include gloves and beanie, good solid boots/hiking shoes, and if you have kids in....  more »
  • This is an amazing experience. I would rate it somewhat difficult. You have to climb down a long rock fall at a moderately steep angle. And once you get down, the floor is very uneven, shoes with ankle support are recommended. A helmet is also a good idea as it is easy to bang your head on some of the low spots. Bring lots of light and more than one. A head lamp is recommended for navigating though the cave but you should also bring something really bright so you can really see the colors and scope of the cave. There are lots of places where you could drop you light and not be able to retrieve it, or if a single light source were to fail you might find yourself in a life and death situation. It is completely dark in there, you can not see anything without a light. If your light fails, and someone does not come along to save you, it might be impossible to find your way out. It is not that there are multiple tunnels that you could get lost in, but how would you even know which way to go. You can't just follow the walls as it would be extremely difficult to walk or crawl near them. So bring lots of light!! And it is cold in there, 32 to 40 degrees. But if you take a few precautions, you will really enjoy your experience.
  • Great little hike in the heat of summer. Remember the tube is an out and back trail. (We thought it was a loop under and then back on top) we hiked in sandals which was fine but the rocks gets quite rugged. You would be better served with hiking boots with support. Bring a sweatshirt, it gets chilly. And a good light.

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