Mammoth Lava Tubes

Mammoth Lava Tubes are a series of lava tubes over 2,100 feet long. They are well known and easy to get to, which makes them extremely popular. The largest lava tube is closed in the winter to protect hibernating bats.

Trip Report: June 8, 2012

Mammoth Lava Tubes (Mammoth Cave) is located north of Duck Creek Village in southern Utah midway between Zion, Bryce, and Cedar Breaks. Access is on paved roads except for the last 3 miles, which is on nice dirt roads. We were coming from the north, and there were nice signs pointing the way.

Our gps tried to send us on some roads that didn't exist. To be safe, just follow the signs that say "Mammoth Cave".

There's a bathroom.

And an information kiosk.

The sign reads:

Welcome to Mammoth Cave!

This popular cave was formed by cooling lava and water. It has five entrances and over 2,100 feet of passages.

Mammoth Cave is a popular recreation site with forest visitors. The cave is also frequented by seven species of bats, including two state sensitive species of bats - the Townsend's Big-eared Bad and Fringed Myotis. Other species of bats observed at Mammoth Cave include the Long-eared Myotis, Big Brown bat, Long-legged Myotis, Western Small-footed Myotis, and the Hoary Bat.

Mammoth Cave serves as an important summertime feeding and night roost area for bats, but it is especially important as a winter refuge for hibernating Townsend's Big-eared bats. In Utah, these bats usually hibernate singly or in very small groups (<5), with fewer than 20 per cave. This cave, however, routinely shelters 60 of these bats each winter - one of the largest known aggregations in the state! Although bats and people can coexist in most instances, wintertime caving can disturb hibernating bats. If disturbed too often, hibernating bats may die.

Human visitation to Mammoth Cave during the winter months is increasing. This puts hibernating bats at great risk. To protect these bats, gates ahve been installed across the entrances to the cave's largest tube. The gate is locked and the rest of the cave is closed to humans during the winter months (October-April) to provide protection for hibernating bats when they are particularly vulnerable to disturbances. It is left oven for visitor access the rest of the year.

You park literally on top of one of the lava tunnels.

This is the upper entrance, which gives easy access to Tube 2.

The main entrance.

This picture was taken from down in the main entrance. Mammoth cave splits into 4 lava tubes.

Tube 1 is the largest tunnel. This gate was installed in 2004 to protect hibernating bats. It has a removable gate to allow visitors to explore Mammoth Cave from May-September.

The ceiling height allows you to walk upright the whole way.

Tube 1 is quite cold and has lots of ice in it.

Here's Jeremy holding some ice chunks that were on the floor.

Near the end of the tunnel, the passage gets pretty tight.

After crawling through about 10 feet of breakdown, you can see daylight through another gate.

This gate marks the end of tube 1.

For size:

Right next to the gate, there are some holes that look promising. I crawled into them, but they didn't go very far.

There was a path that looked like it led somewhere, so we followed it.

We were hoping it would lead to another lava tube, but it just spat us out in a lava flow.

Near the end of Tube 1 is the second exit to Tube 2.

This is Tube 2 Exit 2 from the inside.

I followed Tube 2 without Tara. This lava tube is a lot shorter than Tube 1, so you have to hunch over most of the time.

Here's the first exit for Tube 2 from the inside.

Tara was walking back above ground, so I handed her the camera to take a picture of me poking my head up like a groundhog.

Unlike Tube 1, which has a very rocky floor, Tube 2 is very smooth for most of it.

There are a couple of crawls (knee pads were nice).

And that concluded our exploration on Friday night. We set up camp in the parking area and took some pictures of the trees after the sun went down.

The next morning, we looked for the other passages. We followed an obvious trail to the southwest and ended up at the exit to Tube 3.

Tara was 6 months pregnant and didn't feel like doing any belly crawls, so I did this Lava Tube 3 by myself.

This picture is looking from the Tube 3 exit back to the main entrance of Mammoth Cave.

Tube 3 Exit from inside.

The first part of the tube is fairly tight. You can just barely see daylight from the exit in the picture below.

Tube 3 is about 4 to 5 feet tall, so you're hunched over most of the time.

This passage is interesting because the lava has several different colors: tan, white, and black.

Approaching the main entrance.

Tara met me at the main entrance.

The main entrance looking at Tube 3.

Saturday morning, we had the whole place to ourselves. Bet you can't guess which car is ours.

The upper entrance.

Tara standing below the upper entrance at the convergence of Tubes 1, 2 and 4.

Before we headed out, I wanted to explore the last lava tube. Tara waited in the entrance, while I braved the unknown.

Tube 4 was extremely wet. The ground had several inches of standing water in places. I hopped from rock to rock to log as far as I could go.

Since I didn't bring a spare pair of shoes, I had to turn back before I got to the end of the tunnel. Consequently, I have no idea how far Tube 4 goes and if there is an exit to the surface. We tried walking the surface for a bit but never found the exit.

Muddy footprints several inches deep.

Mammoth Cave was a lot of fun, and we plan on going back.