As evidenced by its tallest, fire-born peaks, Northern Arizona has a volcanic past. You can dig into this geologic history, almost literally, by exploring the Lava River Caves in Coconino National Forest just outside of Flagstaff. The caves were formed 700,000 years ago by a violent eruption that spewed lava into a molten river. As the exposed lava cooled from the outside in, a shell formed around the flow, which remained hot and flowed the rest of the way out, leaving a hollow tube of igneous rock. Today, it forms a cave full of wild lava formations frozen in time.
What Makes It Great
The lava cave is easy to get to and easy to enter, making it a great destination to fill part of a day. The one-way length is about ¾ of a mile, so it doesn’t take long to get through, but you could spend a while examining all the frozen flow features within. Most caves are formed by water, and though this one was created in a very different fashion, some of its formations look very much like normal cave features, while others are completely unusual. Instead of stalactites and stalagmites, there are “lavascicles” and “splashdowns” of liquid rock that froze in motion. Look also for solidified ripples, bubbles, and cooling cracks.
The cave has only one entrance and one main passageway, so it is impossible to get lost. There is one section where the tube forks in two, but rejoins after a short distance. This is the most impressive portion of the cave, a high-ceiling room with wide tubes deviating into the abyss in front of you.
It is of course totally dark in the cave, so bring headlamps and extra batteries. It is also surprisingly cold because winter air sinks into the cave and remains trapped all year. Watch out for ice on the rocks near the entrance.
Who is Going to Love It
This is a great exploration for families and groups of all sizes. It is, for the most part, easy to move around, but the entrance is steep, bouldery, and slick. The rest of the cave has some sharp parts and some slippery parts, so wear good hiking shoes. There are sections with low ceilings that require ducking, but you won’t need to crawl.
Anyone interested in volcanoes and geology will be enthralled by otherworldly igneous formations, and anyone who just loves caves will appreciate the unique nature of this lava cavern.
Directions, Parking, & Regulations
Take Highway 180 north to milepost 230, then turn left on FR 245. follow this for 3 miles and turn left on FR 171. After 1 mile, FR171 veers left at the parking area for the Lava River Cave. These are dirt roads that may be rough and mucky when wet, but are normally passable for passenger cars. The road is closed during the winter.
From the parking lot, follow the trail signs a short distance to the cave entrance. Once inside the cave, enjoy it safely and don’t be destructive to any of the rocks. These were formed hundreds of thousands of years ago and are irreplaceable. Graffiti, breaking formations, and leaving trash are all prohibited because they detract from the natural attraction of the lava cave.