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Explore Flagstaff's Lava River Cave

Flagstaff, Arizona

based on 7 reviews


Added by Jeremy Meek

Venture one mile into the depths of the earth via an expansive lava tube! The tube ranges from 30' tall cavernous passages to narrow passages less than 3' tall.

If you’re looking for a truly unique hiking experience in Arizona, look no further than the Lava River Cave, 14 miles northwest of Flagstaff. The longest lava tube in Arizona, the cave was formed approximately 700,000 years ago after a volcanic eruption in Hart Prairie. As the lava from the eruption flowed, the outer edges began to cool and harden, but the lava in the middle continued to flow, hollowing out the lava rock into a tube. Considered a “natural museum” and a “moment frozen in time,” the cave is a fascinating study in geology, biology, and history — and honestly, it’s just plain cool.

In fact, it’s extremely cool — the lava rock acts as an insulator that keeps the inside of the cave at about 48 degrees or cooler year-round, even in 90+ degree summers. If you have ever dreamed of walking into your refrigerator on one of those summer days, now’s your chance!

The tube itself is a wonder. In some areas, the passages are over 30 feet tall, while in others, the ceiling can be as low as 3 feet (not for the claustrophobic!). There are incredible natural features in the tube, including frozen lava ripples in the ground, and “lavasicles” hanging from above.

From Flagstaff, travel north on US 180. After mile marker 229, you will turn left on Forest Road 245. After approximately one mile, turn left onto Forest Road 171. Shortly thereafter, you will come across forest road 171B; turn left and it will lead to the parking area. From Flagstaff to the cave entrance is about a 30 minute drive. Please note that in the winter months, these roads may be closed due to snow or ice.

The cave itself is approximately one mile long. At the fork in the tube, you can go either way, but going left (north) is easiest. Going right (south) will lead to a very low ceiling that eventually meets back up with the north passage.

Upon entering the cave, you will see evidence of collapses of the tunnel walls. Some collapses happened thousands of years ago, but others are relatively recent. There is always a chance of the walls or ceiling “shedding” layers of rock. As such, do not visit the cave when there have been heavy rains or when there has been recent seismic activity in the Flagstaff area (does not occur often). If you're a worry-wort or always play things safe, bring a spelunking helmet along.

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Easy Parking

Explore Flagstaff's Lava River Cave Reviews

No show cave lighting here. Be sure to have a quality head lamp with charged batteries. This was a great hike to beat the Arizona Heat.

But suuuper scary if you turn off your headlamp. And as a note, make sure you pack extra batteries - the LAST thing you would want would be for your headlamp or flashlight to run out of power.

The first time I visited the lava Tubes as I child I was in awe. It's a really cool place to explore. It can be hot outside but as soon as you're underground in the tunnels, the temperature drops quickly. It's a great summer destination

This was a very enjoyable adventure of mild difficulty. I went on a Friday around noon and there were a comfortable amount of people in the cave. Be sure to register your group at the cave entrance on the Forest Service Registry. There are some points were the cave ceiling is fairly low, but there were a lot of kids, adults, seniors, and dogs enjoying the walk.

We went on a Saturday Morning, and it was incredibly packed, especially at the entrance. All in all, it was really neat. Bring a jacket and extra flashlights!

From highway 180 it is 4.5 miles to the lava cave. Not "approximately one mile" down the road. So when the forest road is closed in the winter and spring months be prepared for a 10ish mile round trip hike.

Leave No Trace

Always practice Leave No Trace ethics on your adventures and follow local regulations. Please explore responsibly!


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