Geologist’s Hike Leads to Prehistoric Discovery in the Grand Canyon

By: Sam Watanuki | Published: Jun 15, 2024

A geological find in the Grand Canyon has stunned scientists and history enthusiasts alike.

During a hike on the Bright Angel Trail, geologist Allan Krill discovered fossilized footprints in a boulder that had been exposed by a cliff collapse. This finding has revealed secrets about prehistoric life that predate the dinosaurs.

The Serendipitous Discovery

Allan Krill, a seasoned geologist, was on a vacation hike with students in 2016 when he spotted a peculiar boulder.

The Grand Canyon National Park seen in Arizona in the daytime.

Source: Anthony Melone/Unsplash

The rock, dislodged from a cliff face, caught his expert eye with its unusual surface markings. Little did he know, this would lead to an extraordinary paleontological discovery.

The Manakacha Formation's Rich History

The boulder Krill found belonged to the Manakacha Formation, a geological layer known for its rich fossil deposits.

An aerial view of Grand Canyon seen in the daytime.

ource: Omer Nezih Gerek/Unsplash

This formation, consisting of mudstone and limestone, dates back millions of years and often reveals well-preserved remnants of ancient life. Krill’s boulder was no exception.

Footprints from the Distant Past

Upon closer inspection, Krill noticed that the boulder’s surface featured a series of fossilized footprints.

Holes seen in the walls of the Grand Canyon that are ancient granaries.

Source: Grand Canyon National Park/Wikimedia Commons

He took photographs and sent them to a paleontologist for verification. The confirmation that these prints were indeed ancient and significant set the stage for a deeper investigation.

Dating Back 313 Million Years

The fossilized footprints were estimated to be around 313 million years old. This discovery was remarkable because it predated the dinosaurs, offering a rare glimpse into life on Earth long before these giants roamed.

A view of the Grand Canyon in Arizona seen in the daytime.

Source: Tim Hart/Unsplash

The prints belonged to a tetrapod, a four-legged vertebrate that lived in a vastly different environment.

Understanding the Grand Canyon's Formation

The Grand Canyon’s geological story spans over two billion years. The Colorado River has played a crucial role in shaping the canyon, carving through layers of rock and soil.


Source: Living Image

This process has revealed countless geological secrets, including Krill’s incredible find.


The Erosive Power of Water

Water, in the form of rain and ice, has been a relentless force in the Grand Canyon’s formation.

A close-up look at dark blue seawater seen in the daytime.

Source: Matt Hardy/Unsplash

Over millennia, the Colorado River’s erosive action has transformed the landscape, creating the vast chasm we see today. This natural process continues to uncover new geological wonders.


The Grand Canyon's Geological Timeline

Geologists believe that the first stage of the Grand Canyon’s formation began about 70 million years ago.


Source: Inspired Imperfection

Tectonic movements uplifted the Colorado Plateau, setting the stage for the river’s erosive work. The timeline, however, was also challenged by a study suggesting a younger age of 5-6 million years.


The Importance of Fieldwork

Krill’s discovery underscores the value of hands-on fieldwork in geology. Despite extensive research and documentation, new findings can still emerge from direct observation and exploration.

An image of an archaeologist using a magnifying glass during an excavation

This emphasizes the dynamic nature of geological studies and the continuous potential for new discoveries.


An Academic Debate

Krill’s find sparked academic discussions about the age and significance of the fossilized footprints.


Source: AZ Highway

Researchers debated whether the tracks were made by one or two reptiles and what these findings imply about prehistoric life. Such debates highlight the ever-evolving understanding of Earth’s history.


A New Tourist Attraction

Today, the boulder with the fossilized footprints has become a notable tourist attraction. Hikers on the Bright Angel Trail can stop to see this remarkable piece of history.

The Grand Canyon seen in the daytime underneath a blue sky.

Source: Gabriel Tovar/Unsplash

This boulder serves as a reminder of the ancient life that once inhabited the region and the ongoing discoveries within the Grand Canyon.


Krill's Legacy in Geology

Allan Krill’s discovery has cemented his name in geological history. His keen observation and dedication to fieldwork led to a find that offers invaluable insights into Earth’s prehistoric life.

The Grand Canyon National Park seen during sunset.

Source: Jennifer Rogalla/Unsplash

The discovery is an example of the importance of curiosity and exploration in uncovering the secrets of our planet.