Lava Caves

I am exiting a lava cave at an undisclosed location in Island Park.

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I would have never seen them if it hadn’t been for an extremely cold and clear day. The snow-covered Sand Creek Desert, full of buttes and lava flows, seemed to be breathing like a dragon. Through the binoculars, I could see plumes of steam rising from the ground and climbing a few yards above the surface before dissipating in the frigid air. These plumes marked places where warmer air from beneath the ground surface was escaping into the atmosphere. We were pretty sure that we could see the mouths of the Civil Defense and Ice Caves where major plumes of steam arose, but were the other ones cave openings too?

As one of the world’s major building blocks, lava leaves behind many different types of figures from spatter cones, pit craters and sinkholes, rhyolite domes (Big Southern Butte for example) and sheets of lava many miles wide and long. Sometimes though, there is an entirely different world beneath these obvious evidences of volcanism.

Lava tubes or lava caves, are remnants of surface lava movement. Most lava is thin, running like thickened water once it erupts from a vent or weak spot in the surface. Like a river, it will run downhill, following the path of least resistance. And, like a river, the center will run faster than the sides.

This is the basic set up for the creation of a lava cave. Like ice forming on a river, the slower moving sides begin to cool and harden while the molten lava continues to move in the center. Eventually, the cooling extends from each side until the river of lava is capped with solid lava just like winter ice. Inside, entrapped lava becomes superheated and continues to flow, often eroding the bottom of the channel deeper and deeper (called thermal erosion) until the eruption ends.

At this point, the remaining lava flows out of the space and is not replaced, leaving a lava tube. The last remnants of the flowing lava often create a jumble of rocky lava blocking the end of the cave. As time passes, other lava flows may cover the tube, burying it deep beneath or sometimes even filling it. This has happened several times to mapped caves in Hawaii’s Volcanoes National Park. Those caves that are deeply buried are unlikely to be discovered. Shallower caves are often revealed when a thin spot in the roof collapses.

The features inside a lava cave will not be like those of a limestone cave. There is no dissolution and re-solidifying of limestone to create stalactites, stalagmites, curtains or bacon. Inside a lava cave, look for changes in the lava that might indicate the change in lava levels as the tube emptied or features created as the lava dripped and hardened.

Lava caves are usually a single long chamber. However, there are examples of lava caves with multiple caverns and levels. The Catacombs Cave in Lava Beds National Monument in the Cascade Mountains of northern California, is a great example. This 6,903-foot-long cave has multiple branches and a map is recommended for visitors.

While lava caves are typically relatively short, the longest mapped lava cave in the world is Kazumura Cave in Hawaii, a cave system that is 40 miles long with passages sometime exceeding 25 feet in width.

It may take a year or more for this lava tube to cool enough for colonization to begin, but in short order, a number of cave-loving creatures, collectively called troglobites, begin to inhabit the caves. There are often slimy mold-like substances that colonize lava caves and many species of bats also use lava caves for roosting and hibernation.

In our area, Craters of the Moon National Monument has several short lava caves. Our most famous lava caves are probably the Civil Defense Cave and Ice Cave north of St. Anthony off the Red Road.

It is highly unlikely that all the caves in our area have been discovered. As my experience last December on the Sand Creek Desert indicated, there may be dozens of caves waiting to be revealed. If you do discover one though, you might want to keep it a secret. Life in these caves can be fragile and human exploitation can quickly alter that.

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Help Idaho Wildlife

When we traveled across the state in October 2017, most of the vehicles we saw using the wildlife management areas did not have wildlife plates. Buying wildlife plates is a great way for non-hunters and hunters alike to support wildlife-based recreation like birding.

C'mon folks, let's help Idaho's wildlife by proudly buying and displaying a wildlife license plate on each of our vehicles! 

See below for information on Idaho plates. Most states have wildlife plates so if you live outside Idaho, check with your state's wildlife department or vehicle licensing division for availability of state wildlife plates where you live. 

And tell them that you heard about it from Nature-track.com!

Wildlife License Plates

Great news! as of 2024, there are three NEW designs for license plates. They still are bluebird, cutthroat trout and elk, but they are beautiful.

Idaho Wildlife license plates provide essential funding that benefits the great diversity of native plants and wildlife that are not hunted, fished or trapped—over 10,000 species or 98% of Idaho’s species diversity. Game species that share the same habitats (such as elk, deer, antelope, sage-grouse, salmon, trout) also benefit from these specialty plates.

No state tax dollars are provided for wildlife diversity, conservation education and recreation programs. Neither are any revenues from the sale of hunting or fishing licenses spent on nongame species. Instead, these species depend on direct donations, federal grants, fundraising initiatives—and the Idaho Wildlife license plates.

Both my vehicles have Bluebird Plates. I prefer the bluebird because the nongame program gets 70 percent of the money from bluebird plates, but only 60 percent of the money from elk and trout plates - 10 percent of the money from elk plates supports wildlife disease monitoring and testing programs (to benefit the livestock industry) and 10 percent from cutthroat plates supports non-motorized boat access.

Incidentally, in 2014, the Idaho Legislature denied the Department of Fish and Game the ability to add new plates or even to change the name of the elk and cutthroat plates (very specific) to wildlife and fish plates, a move that would have allowed for changing images occasionally and generating more revenue. It would seem that they believe that we Idahoans don't want a well funded wildlife program.

I think it is time we let the Legislature know that Idahoan support wildlife funding and that we would like to see these generic plates come to fruition.