National Park Service

U.S. Department of the Interior

Cinder Cones, Lava Flows, and Lava Tube

Mojave National Preserve

Driving across the Mojave Desert on Interstate 15 or Kelbaker Road, visitors might notice 

a series of peculiar features on the horizon: thirty-two conical mounds of red and black 

volcanic rocks rise abruptly above the desert landscape. Surrounded by a sea of hardened 

lava flows, these little volcanos—cinder cones—began erupting into existence 7.6 million 

years ago. Lava last flowed just 10,000 years ago. Abundant and well preserved, these geologic features were designated as Cinder Cone National Natural Landmark in 1973.

Introduction

Soda from a Cinder Cone Millions of years ago, fountains of liquid magma 

erupted through vents in the earth’s crust beneath 

present-day Mojave National Preserve. Much like 

the opening of a shaken can of soda pop, hot, pressurized magma spewed skyward. Upon contact with 

cool air, the magma instantly solidified, preserving 

the bubbles created by escaping gases. The light, 

hole-filled rocks, or cinders, accumulated around the 

vent and formed a cone-shaped hill. When the growing piles of cinders became too steep, avalanches 

created the roughly 30-degree slopes evident today.

Unlike a can of soda pop, which erupts for only a 

brief moment, the fountains that create cinder cones 

can last months, or even years. As subterranean pressures decrease and the eruption comes to an end, 

black basaltic lava may slowly flow from the vent, 

oozing out across the landscape.

Today, basalt formed from such lava flows can be 

seen among the cinder cones. Most flows are 10 to 

13 feet thick, and exhibit both ropy (pahoehoe) and 

blocky (aa) surfaces.

Recipe for a Volcano Volcanic eruptions don’t occur everywhere. Several 

“ingredients” must combine at the right place and 

time. While the geologic complexities of Southern 

California are still under investigation, many researchers think that faulting, block movement, and 

associated magma production are key ingredients 

contributing to the recipe for cinder cones and lava 

flows in Mojave National Preserve.

During the Mesozoic Era (~245-65 million years ago), 

extensive tectonic activity in western North America 

resulted in a dynamic period of volcanism and faulting as the Pacific Plate began to slide beneath the 

North American Plate. Then, around 30 million years 

ago, great fault systems developed further throughout 

present-day California. Regional movement of these 

faults cracked the earth’s crust into blocks.

As the plates and blocks of the earth’s crust slide 

and rotate, they generate friction and tremendous 

heat. Beneath the Mojave, rocks of the lower crust 

melted. Because it is less dense than the surrounding 

rock, the melted, mantle-derived basalt, or magma, 

rises toward the surface. When magma cannot find a 

path upwards it pools into magma chambers. These 

chambers can be huge, providing enough magma for 

many volcanos over several years. To form a volcano, 

however, magma must reach the surface.

The spaces between fault blocks are zones of weakness reaching down to the mantle. Pressure within 

magma chambers was released as eruptions through 

such fractures or vents in the earth’s crust, providing 

magma with a way up and out. With this final ingredient, a hot and “fresh” volcano is formed. 

Flows, Tunnels, & Tubes Not all lava is the same. Very thick, gooey rhyolitic 

lava doesn’t flow very far. The runny basaltic sort 

that characterizes some of the lava flows of Mojave 

National Preserve, however, spreads out as smoothly 

as hot maple syrup. It flowed from the sides of the 

cones or pooled near their bases.

As the lava streamed out across the land, it slowly began to cool. Often, the top of a flow would cool while 

liquid lava continued moving underneath, creating a 

tunnel. When the eruption ended, the flowing lava in 

the tunnel either cooled in place or emptied out the 

tunnel’s end, leaving a hollow lava tube.

A lava tube is accessible via a 5-mile drive from Kelbaker Road. Climbing through a collapsed hole in the 

tube’s roof, visitors have a rare opportunity to view 

this river of rock from the lava’s perspective.
Directions to Lava Tube The lava tube is located about 5 miles east of Kelbaker Road on the unpaved and unsigned Aiken Mine 

Road. A High clearance vehicle is recommended.

To Aiken Mine Road:

From Interstate 15:

19 miles south of Baker, Calif. on Kelbaker Road; turn 

north (left) onto Aiken Mine Road.

From Interstate 40:

28 miles west of Ludlow, Calif., turn north onto Kelbaker Road; continue 23 miles to Kelso Depot Visitor 

Center (see below).

From Kelso Depot Visitor Center:

15 miles north of Kelso on Kelbaker Road; turn north 

(right) onto Aiken Mine Road.

From Jct. of Kelbaker & Aiken Mine Roads:

Follow Aiken Mine Road, passing an old water tank 

and corral after 1.6 miles. At about 4.5 miles, bear left 

at a fork in the road. Continue another 1/4 miles, past 

a horse corral to the left, to where the road widens 

into a circular parking area.

From the parking area, walk uphill on a very rough 

roadway about 300 yards to a rock cairn (may not be 

visible) or metal post marking a beaten path toward a 

cinder cone to the east (right). This trail leads to the 

lava tube entrance.

The lava tube is not maintained by the National 

Park Service. Enter at your own risk.

Map

E X P E R I E N C E Y O U R A M E R I C ATM

Hiking trail

Cinder cone

Lava flow

Unpaved dirt road

Paved road

Interstate

15

15

127

Kelso Depot

Visitor Center

P R E S E R V E

SILVER

LAKE

(dry)

K

Bull Springs Wash

Black Tank Wash

Qua

Sprin

MOJAVE ROAD

UNION PACIFIC RAILROAD

Ludlow

Baker

Kelbaker Road

Zzyzx

Road

Kelbaker Rd

Kelso

Cima

Road

Cima

Road

Aiken Mine Rd

Kelbaker Road

Kelso

Dunes

Trailhead

Teutonia

Peak Trail

1

2

15mi

24km

19mi

30km

28mi

45km

3mi

5km

12mi

19km

26mi

42km

5mi

8km 14m

23k

To I-40

23mi

37km

Baker to Furnace Creek,

Death Valley National Park

113mi 182km

300yds

Horse Corral

Lava Tube Trail

Rough Roadway

Lava Flow

Lava Flow

LAVA TUBE

Cinder Cone

North

Water Tank

& Corral

LAVA TUBE

Zzyzx

Desert Studies Center

Halloran Springs 

G R A N I T E

M O U N T A I N S

CINDER CONE

NATIONAL NATURAL

LANDMARK

S

H

A

D

O

W

V

A

L

L

E

Y

KELSO DUNES

MOHAWK HILL

Turquoise

Mountain

4511ft

1375m

Solomons

Knob

Wildca

5179ft

1579m

Clark Mountain

7929ft

2417m

Halloran Summit

4000ft

1219m

0

0 5 10 Miles

5 10 Kilometers North

Salton

 Sea

Co ol rado River

Joshua

Tree NP

Mojave

National

Preserve

Los Angeles

Flagstaff

Needles

Kingman Barstow

Phoenix

15

5

5

10

40

40

17

93 95

395

58

14

14

177

95

62

C A L I F O R N I A

A R I Z O N A