Lava River Cave Is Cool in Every Sense of the Word

When summer temperatures climb past 110 in the Valley, Lava River Cave sits at a steady 40 degrees. This mile-long lava tube northwest of Flagstaff was carved by volcanic flows roughly 700,000 years ago, and it has been waiting quietly ever since. On a weekday morning, you will likely have most of it to yourself.

What You Are Walking Into

Lava River Cave is a lava tube, a tunnel formed when the outer shell of a molten flow hardened while liquid rock continued to drain through underneath. When the lava drained away, it left a hollow passage about a mile long and tall enough to stand upright in for most of the route. There are no lights, no rails, no ranger escorts, and no cell service once you are inside. That is the point. This is about as raw as a public cave experience gets in Arizona, and visitors who expect that tend to love it.

Come Prepared or Do Not Come

The Forest Service is direct about this, and so will we. Bring at least two light sources per person, ideally three. A headlamp plus a backup flashlight is the minimum. If one fails in the dark, you will want the other. The ground is uneven volcanic rock throughout, and there is no artificial lighting anywhere in the cave. Sturdy, closed-toe shoes with good ankle support are essential. The cave holds between 35 and 45 degrees Fahrenheit year-round, which sounds pleasant in July but will surprise you after the first ten minutes. Bring a jacket or a light layer you can tie around your waist on the walk in. The Forest Service also recommends a hard hat or helmet, as ceilings drop in a few sections. No pets are allowed.

When to Go

Summer is the obvious draw. When Flagstaff is warm and Phoenix is miserable, a 40-degree cave is a genuine relief. The trailhead is accessible from late spring through fall when Forest Roads 245 and 171 are open. In winter, those roads close due to snow and mud, and accessing the cave requires a four-mile one-way hike or ski from State Route 180. Unless winter cave adventure is your particular thing, plan for May through October. Weekday mornings in June, July, and August are the sweet spot: cool inside, manageable outside, and far fewer families with children than you will encounter on a weekend.

Getting There and What It Costs

The cave is located about 9 miles northwest of Flagstaff off Highway 180. From there, you take Forest Road 245 to FR 171. The roads are unpaved but generally manageable in a standard vehicle when dry. Parking is at the trailhead, and a short walk leads to the cave entrance. A day-use fee of $5 per vehicle applies. America the Beautiful and Red Rock passes are accepted. Fee machines are on site, so no advance purchase is required. There are restrooms and picnic tables near the entrance, which visitors consistently mention as a welcome convenience.

How Much Walking Is Involved

The cave itself is one mile long one-way. Most visitors walk in as far as feels comfortable and turn back, which is completely fine. The floor is uneven rock throughout, and the path narrows and the ceiling drops in places toward the far end. There is no loop. Plan on 1.5 to 2 hours inside depending on pace and how far you go. The effort level is moderate: no significant elevation change, but the footing requires attention. If balance or stability is a concern, use trekking poles and watch your step on the rougher sections near the back of the tube.

Quick Picks