White Sands National Monument

White Sands National Park Service

U.S. Department of the Interior

Have you ever wondered what this area, the Tularosa Basin, looked like 30,000 

years ago? Was it a desert like today—or was it 

perhaps lush with lots of plants and animals? 

Our present day desert was once a verdant land 

teeming with prehistoric plants and animals. 

The climate during the Pleistocene epoch was 

much wetter and cooler than today. Rain and 

snowmelt filled a 1,600 square mile lake called 

Lake Otero. This lake was larger than great lakes 

Erie and Ontario combined! Clues of this past 

oasis are found in the ephemeral trackways left 

behind by the Pleistocene giants that once called 

the Tularosa Basin home. Scientists are studying 

these trackways to gain a better understanding 

of this ancient ecosystem and the mighty 

mammals that ruled the day. 

The Pleistocene

Trackways of White 

Sands National 

Monument

First Discoveries

In 1932, Ellis Wright, a government trapper, 

found large tracks on the west side of the 

White Sands. He thought that he had 

discovered the tracks of a giant human! Each 

track was approximately 22 x 10 inches, the 

size of a rectangular place mat. Subsequent 

investigators thought that the tracks were 

indeed human because the print was perfect 

and even the instep was clearly marked. 

It was not until 1981 that further investigation 

of the tracks identified them as mammoth, 

giant camel, and an undetermined 

mammal. During a tour by the New Mexico 

Archaeological Council in June of 1984, a 

large mammoth molar fragment was observed 

in a small gully within 800 feet of one of the 

mammoth tracksites. Unfortunately, there is no 

record that the fossil was ever recovered.

In 2001, tracksites in the monument were reexamined. Tweny-five mammoth tracks and 

64 camel footprints from the late Pleistocene 

epoch were discovered. Additional trackways 

were also discovered on the southern shore of 

Lake Lucero. There were hundreds of them, all 

of which were nearly east-west in orientation. 

Unfortunately, the tracks were poorly preserved 

in the soft gypsum. Their age was determined to 

be about 30,000 years old by carbon dating the 

seeds and other plant matter embedded in the 

track itself. These tracks pre-date the arrival of 

humans in the area by about 20,000 years. 

Since 2007, researchers and monument staff 

have discovered even more fossilized tracks 

within the monument. They may represent the 

largest concentration of Pleistocene trackways 

in the United States. They appear to be primarily 

from mammoths, camels, dire wolves, and 

saber-toothed tigers. While most of them 

pre-date humans in the area, a few recently 

discovered sets of fossil tracks appear to be 

associated with archaeological artifacts. This 

suggests the possible co-existence of humans 

and mammoths in the basin. The majority of 

the fossil tracks suggest that the ancient animals 

traveled to and along the shorelines of Lake 

Otero and across the surrounding wetlands 

during the late Pleistocene. 

What We Are Learning Now

A lot was going on during the late Pleistocene. 

It was during this period that our earliest 

human ancestors appeared and gradually 

evolved into Homo sapiens. By this time, the 

continents had moved into their modern 

positions and one of the last major Ice Ages 

shaped the land through dozens of interglacial 

and glacial periods. In North America, glaciers 

advanced and retreated, sometimes extending 

all the way down into New Mexico. Large 

mammals (megafauna) were plentiful and the 

climate dramatically shifted, changing from 

cool and moist to hot and arid. 

Pleistocene Epoch Happenings

Tracks found in the monument are preserved 

in gypsum layers and are quite fragile. Once 

exposed from beneath the sand, the tracks 

weather rapidly. Many of the recently found 

tracks have already eroded and disappeared. 

Because they breakdown so quickly, 

monument staff is working with experts 

to develop a strategy for conservation and 

monitoring of the tracks. Their scientific 

significance underscores the need for 

continuing research into these incredible 

and rapidly vanishing natural wonders.

What Does the Future Hold?

Pleistocene

Epoch 

Holocene

Epoch

1.7 mya 10,000 ya

Q

u

a

t

ern

ary

P

erio

d

Present

Images are to scale

Columbian Mammoth

Ancient Camel

Saber-toothed Tiger

6ft Man

Dire Wolf

Weathering of exposed mammoth tracks

2009 2010 2011

Scan for an in-depth explanation of the 

geologic story of White Sands and the 

Tularosa Basin.
Images are to scale

Mammoths 

Mammuthus primigenius

Mammuthus columbi

Mammoth species in North America 

included the Wooly mammoth (Mammuthus 

Primigenius) and Columbian mammoth 

(Mammuthus columbi). Tracks from both 

species have been found in White Sands but the 

majority are from the Columbian mammoth.

Both mammoths were herbivores, eating 

mostly grass but grazing on other types 

of plants as well. Like today’s elephants, 

they ate 600 pounds of food and drank 

40 gallons of water daily. In fact, they 

spent 16–18 hours a day either feeding or 

moving toward a source of food or water. 

Like modern elephants, mammoths used 

their tusks to dig and collect food and to 

intimidate and fight off predators and rivals. 

Their tusks began to form at birth and grew 

throughout their lifetime, gaining a new 

layer each year. Like tree rings, changes in 

tusk growth rate generally reflect changes 

in the animal’s nutritional condition. 

The ancient western camel evolved rapidly 

between 33mya and 12mya, finally developing 

into Camelops hesternus. Originating in 

North America, camelops probably looked 

like a large dromedary, a modern-day onehump camel. It went extinct around 11,000 

years ago, probably due to pressures such as 

increased hunting and global climate change. 

Weighing in at around 1,764 pounds, camelops

would have dwarfed its modern cousin, which 

weighs around 1,433 pounds. Its limbs were 

also longer and its estimated shoulder height 

was seven feet. Like modern camels, it was an 

opportunistic herbivore that would eat any 

vegetation it could reach. Although modern 

camels are known for being able to survive 

for long periods without water, it is unknown 

whether camelops was able to do the same.

Camels

Camelops hesternus

Known for its large canines, one species of 

saber-toothed tiger, Smilodon fatalis, stalked 

the Tularosa Basin until about 10,000 years 

ago. Unlike its colloquial name suggests, it 

was not related to any modern feline species. 

It was, however, larger and had a more 

robust build than modern “big cats” such 

as tigers, lions, leopards, and cougars. 

As frightening as its canine teeth may look, 

Smilodon’s bite was relatively weak. The 

larger teeth reduced the space available for 

jaw muscles, reducing bite pressure. Biting 

down too hard on a prey animal could result 

in the breakage of one of its canines.

Smilodon’s bob-tail suggests that did not 

chase down prey like lions or tigers whose 

long tails help them maintain balance 

while running. Instead, they were more 

likely opportunistic hunters, hiding in tall 

grasses and ambushing prey animals. Its 

diet would have included prehistoric deer, 

bison, and an occasional mammoth. 

Saber-Toothed “Tiger”

Similodon fatalis

Looking very much the modern-day gray 

wolf, the dire wolf hunted the grasslands 

of the basin until around 10,000 years 

ago. Similarities between the two species, 

however, stop at appearances. 

The dire wolf was much heavier and had 

powerful bone-crushing jaws and teeth. Its 

legs were shorter and its shoulder blades 

more massive than the modern gray wolf. 

Weighing between 125 and 175 pounds, it 

was about the size of an English Mastiff—one 

of the biggest and heaviest dogs recognized 

by the American Kennel Association. 

The dire wolf’s rear teeth were adapted 

for tearing, not chewing. This suggests that 

it did not chew its meal but tore off large 

chunks of flesh and swallowed them whole. 

They were not picky eaters so any animal 

available was on the menu. Larger animals 

like bison could also be taken down by 

hunting in packs of 30 wolves or more. 

Dire Wolf

Canis dirus

c. Sergiodlarosac. Sergiodlarosa

c. Sergiodlarosa

c. Sergiodlarosa

Columbian Mammoth

Saber-toothed Tiger

Ancient Camel

Dire Wolf

6ft Man

6ft Man

revised 9_23_13