NSS Convention ~ July 25-30, 2021

Lava Beds National Monument

Quick Read:

A part of the Medicine Lake Highlands, Lava Beds National Monument has been an exceptionally popular destination for western cavers for many decades. Through both our recreational and scientific collaborations, this park holds a special place in our hearts. CRF and NSS cavers actually helped raise the money to build the park's research center! If you have the opportunity during your convention visit - don't miss this one!

All visitors MUST stop by the visitor center for a free permit before entering any caves. If you don't pick up the free permit, you may be cited by federal rangers for going caving. We think the park's 850+ caves are worth a few easy rules.

Lava Beds Cinder Cone

Welcome to Lava Beds!

This is a land of turmoil - both geological and historical. Over the last half-million years, volcanic eruptions on the Medicine Lake shield volcano have created a rugged landscape dotted with diverse volcanic features. More than 850 caves, Native American rock art sites, historic battlefields and campsites, and a high desert wilderness experience await you!


Lava Beds National Monument protects a wide variety of well-preserved lava features resulting from many eruptions of the Medicine Lake shield volcano over the past 500,000 years - including cinder and spatter cones, "lava beds", and over 850 lava tube caves. These features result from a tectonic plate beneath the Pacific Ocean slowly sliding under the continental plate. As it dives deep into the earth, this oceanic plate melts into magma, which then rises to the surface as lava several hundred miles inland from the coast. The Medicine Lake volcano is one of many places where these eruptions occurred throughout the Cascade Range of volcanoes, which stretches from northern California into British Columbia.

Medicine Lake is unique among Cascades volcanoes for its great surface area, as well as the wide variety of features left behind by eruptions of different characteristics and composition. These special places are yours to explore both here and throughout the surrounding area. Please remember that the unique geology of Lava Beds belongs to everyone, and rock collection is prohibited.

Lava Beds lies on the northern flank of the Medicine Lake volcano and covers only about 10 percent of its surface area. At approximately 150 miles around the base, 7900 feet in height, and covering over 700 square miles, Medicine Lake is by far the largest volcano by volume in the Cascade Range. It is believed to have many small underground magma chambers rather then one large chamber. Eruptions from nearly 200 surface vents have created a volcano with a low, broad, gently sloping profile - like a shield. This profile built up over time by relatively mild eruptions of fluid lava flowing over large areas. The amount of gas and certain chemicals present in magma also contribute to the way a volcano erupts.

Crystal Ice Cave

Lava Beds National Monument is home to Crystal Ice Cave. This lava cave drops as deep as 150 feet below the ground and runs 960 feet long, and features towering ice stalactites, stalagmites, and two frozen waterfalls. Video courtesy of Midpines Media.

Current eruptions on the Hawaiian islands are a good example of what the Medicine Lake volcano looked like as it formed. By contrast, composite, or strato-, volcanoes are what many people think of when they hear the term "volcano". Familiar composite volcanoes of the Cascade Range include Mounts Shasta, Lassen, Mazama (Crater Lake), St. Helens, and Rainier. These volcanoes result from layers of lava and ash that pile up primarily around one central vent, creating the characteristic pointed cone. These eruptions are often violent, and may include the ejection of large amounts of ash, pyroclastic materials such as hot rocks, and even massive mudflows (lahars) if glaciers on a volcano's peak melt quickly.

The Medicine Lake volcano has erupted intermittently for approximately half a million years. The most recent flows of pumice and obsidian at Glass Mountain (south of Lava Beds in the Modoc National Forest) occurred less than 900 years ago. Since there have been no eruptions within historical times, and there are no signs that the volcano is getting ready to erupt soon, geologists consider Medicine Lake "dormant". However, since the tectonic forces beneath all the Cascades volcanoes are still in motion, it is likely that there will be an eruption here again sometime in the future. Perhaps Native Americans watched as the volcano came alive here hundreds or thousands of years ago, and fountains of glowing rock fed rivers of fire that poured over the landscape. Perhaps future generations will witness this awesome spectacle again someday.

Today you can see the hardened results of over thirty separate lava flows exposed at Lava Beds. Rocks visible within the Monument range from two million year old volcanic tuff at Gillem Bluff in the northwest corner, to basalt about 1100 years old at the Callahan Flow in the southwest corner. Multiple eruptions of liquid basalt that flowed from Mammoth and Modoc Craters (on the Monument's southern boundary) between 30,000 and 40,000 years ago formed most of the lava tube caves here. This flow covers about 70 percent of the Monument. A different flow in the southeast corner of the park that emerged around 11,000 years ago was lower in viscosity and created smoother-textured caves, including Valentine Cave. Cinder cones, spatter cones, and other surface lava flows also appeared periodically between every few hundred and every few tens of thousands of years.

Caver to Caver

Lava Beds Natl. Monument

There's WAY more to see here than you can accomplish in a couple days. But first things first - seriously, stop by the Visitor Center and get a free caving permit. WNS fungi have been detected about 3 hours from here & everyone is running on edge these days. Then...

If you only have a few hours, do Cave Loop Road. It's touristy, but you can still have a lot of fun. Definietly see Golden Dome Cave, Hopkins Chocolate Cave, Catacombs Cave, Sunshine Cave, and Upper and Lower Sentinel Caves. If you plan to do the tight crawls, use knee and elbow pads that you don't mind trashing. This lava can be nasty mean.

If you have a full day, Skull Cave is impressive because it's so huge. It won't take long, but go all the way to the back gate and see the ice floor. Symbol Bridge Cave is off the same road and has some stunning petroglyphs. Mammoth Crater is impressive as well - it's the source of all the caves in this area. A steep hike up Schonchin Butte offers great views of the surrounding region.

If you plan to overnight, the park offers a dry campground (for a fee), or you could just drive a couple miles past Mammoth Crater into the Modoc National Forest & find a freebie campsite off the map (it's still dry, but there's more shade there!). NO campfires, please - we don't care what the signs say, it's dangerous!

The nearest store is in Tulelake (they have an amazing alcohol collection). Be sure to double (or triple) the amount of survival water you think you need. This high-desert ecosystem will suck it out of you in no time at all.

PS - You probably won't see any, but please don't pet the rattlesnakes. They hate that.

Click here to download a map to the caves.

Lava Tube Caves

A gentle slope and very fluid lava are required for the formation of lava tubes. Lava up to 2000°F flows downhill and immediately begins to cool and solidify upon contact with the ground and air. Lava touching the ground solidifies first, followed by the sides and then the top of the flow. This hard shell of cooled lava insulates the liquid rock inside, allowing it to flow long distances before it cools and comes to a stop. The lava continues to flow until it either drains out or seals the end of the tube. Imagine when lava tubes extended largely unbroken for up to 10 miles from Mammoth Crater, stopped only by the waters of Tule Lake! In the millenia since, weather and gravity have punched holes in the ceilings of these extensive tube systems every few hundred feet, leaving behind almost 700 individual caves. These caves now provide not only outstanding opportunities for exploration, but habitat for a host of species ranging from threatened bats and bacteria, to tree frogs and sword ferns that cannot survive in the dry surface environment. The perennial ice formations found in some caves also give scientists an opportunity to study the effects of climate change.

Cinder Cones
The rounded mounds of many cinder cones dot the Lava Beds landscape. A cinder cone forms when high pressure and dissolved gases in magmacause an eruption that blows a fountain of lava into the air. The cooling lava then falls as cinders around the vent. Many cinder cones also ooze liquid lava from their bases if the eruption's underground magma source changes character, such as the Schonchin Lava Flow emanating from Schonchin Butte. This is the only cinder cone with a trail to the top; please help preserve others by not climbing on them.

Spatter Cones
Sometimes thick blobs of lava resembling lumpy oatmeal are thrown out of a vent. Thicker than cinders and thrown less high into the air, they form a cone where they land. Black Crater is an example of an impressive spatter cone. A hollow chimney may also form where the lava emerged - those found at Fleener Chimneys are 150 feet deep.

Mammoth Crater once contained a massive lake of lava that overflowed rather than erupted, and left behind an enormous empty crater. The highly fluid, basaltic lava was transported many miles to the northern part of the monument, creating networks of lava tube caves all along the way.

Fault Scarps
Gillem Bluff is an example of a fault scarp, a place where large blocks of crust move relative to each other, sometimes during violent earthquakes. Many long cliffs or ridges in this area are found along faults. Gillem Bluff has moved up relative to the basin below, exposing layers of ancient basalt believed to be two million years old.

2020 Caldwell Fire

2020 Caldwell Fire. Photo: National Forest Service.

2020 Caldwell Fire. Photo: National Forest Service.

On July 22, 2020, firefighters from the Modoc National Forest began responding late in the evening to several reported lightning fires near Lava Beds National Monument. These lighting fires started after a series of strong thunderstorms moved through the area. While most fires on the Modoc National Forest are kept relatively small with swift containment efforts, this incident quickly spread through the dry forested areas.

The 2020 Caldwell Fire - near Caldwell Butte southeast of the Lava Beds - burned in an area that had not seen fire in over 40 years. Dense Ponderosa and Lodgepole Pine stands were quickly overtaken. Over several days of significant fire behavior and growth, the Caldwell fire consumed over 80,859 acres before it was contained.

Monument staff was allowed back in the park in early August. As of this writing, no biological impact studies have been conducted. Current presumption is that the caves will suffer limited impact, but the fate of several maternity colonies of bats in the park remain to be determined. Over the winter of 2020-2021, favorable precipitation could lead to an extensive display of wildflowers as the park's ecosystem starts to recover next summer.

Hopkins Chocolate Cave

Today's Weather: Lava Beds National Monument, CA

  • Updated: Saturday, June 12 at 6:17 am
  • Reporting Station: VAN BREMMER (VABC1)
  • Elevation: 5,303 ft.
  • GPS: 41.642967;-121.794875
  • Data provided by: National Weather Service
46° F
Mostly Clear

Regional Map Forecast Wind: 18 mph (SSE)
Humidity: 83%
Dewpoint: 41°F
Barometer: N/A
Visibility: N/A

Overnight: Mostly clear, with a low around 46. South southwest wind around 3 mph.
Saturday: Sunny, with a high near 76. South southwest wind 3 to 16 mph, with gusts as high as 24 mph.