Mammoth steps found at Fossil Lake
Almost 43,000 years ago, a herd of Columbian mammoths made their way across the ice in Central Oregon lumbering through the cold; one of them limping badly due to a leg injury.
Today, their movements have been rediscovered, the first such records of tracks found in an area of Lake County popular among fossil hunters that has earned the moniker Fossil Lake.
An area where a vast array of fossils were discovered in 1870 by Dr. Thomas Condon — one of the founding instructors at the University of Oregon — the site east of Christmas Valley has seen many fossil hunters, archaeologists and students return each year in search of new discoveries of ancient records that have helped reshape human understanding of the ancient world.
The area has not only provided thousands of fossils, but also a petrified wood forest. Not far away, near Fort Rock, sandals created by humans more than 10,000 years ago were discovered in a cave — among the earliest record of humans in the Western Hemisphere.
While many groups have returned to research labs with plenty of bones in tow, what was found last summer astounded a collective from the University of Oregon.
The area, approximately 66 feet long and 25 feet wide in the remote desert, features perfectly preserved tracks left by long-extinct massive creatures that once dominated the central Oregon landscape — the Columbian mammoth.
The site features remnants of the ancient animal’s footprint trails, called trackways, and imprints of ancient soil, known as paleosols.
Findings of that discovery were recently published in the journal “Palaeogeography, Palaeoclimatology, Palaeoecology” as part of an advanced scientific understanding in the behavior of Columbian mammoths and the environment of Pleistocene-era central Oregon.
The study was led by Greg Retallack, a University of Oregon professor from the university’s Museum of Natural and Cultural History, along with several students in collaboration with the Bureau of Land Management and University of Louisiana-Lafayette.
Retallack’s expedition in July last year found 117 mammoth tracks, with particular interest in a line of 39 prints from an apparently injured adult female mammoth. While fossils are common finds at the site, according to Retallack it was the first time that trackways had been discovered at Fossil Lake.
“Tracks sometimes tell more about ancient creatures than their bones, particularly when it comes to their behavior,” said Retallack. “These prints were especially close together, and those on the right were more deeply impressed than those on the left — as if an adult mammoth had been limping.”
Beyond the fossil
Nearby trackways suggested that the preserved marks were placed thousands of years ago by a herd of mammoths, providing important clues to behavior of the creatures that can’t be determined by fossils alone.
The behavior offered clues to the gait and age distribution of the herd as well as juveniles returning to the side of an injured adult. It matches behavior patterns still found today in African elephants.
Beyond just footprints, students also dug pits to study soil of the area, which shed light on the environment in the region when the mammoths made their trek through the Christmas Valley.
During the last great ice age, Columbian mammoths and ancient horses survived on lowland grasses in an environment that at the time showed to be dry in summers, with larger lakes than there are currently, and endured more significant snowfall.
The desertification of Fossil Lake and its surrounding area, once lush grasslands, Retallack concluded, was a consequence of the extinction of large animals like the Columbian mammoths around 11,500 years ago. The large animals’ trampling and grazing kept less-tolerant plant species from thriving. Today the area is renowned for its grasses, as the alfalfa hay grown by farmers in the region is considered some of the finest in the world, and is highly sought on the international market.
A thriving environment
Calling Fossil Lake a body of water is a bit of a misnomer, as there is no visible surface water anywhere to be found in the remote and arid high desert.
However, the area once thrived as a large body of water, and in the wake of it drying up so many fossils of the lake’s past have been discovered since Condon’s first visit that it has been declared one of the most important sites of vertebrate paleontology on the planet.
Documentation of the trackways, which also included identified prints of an ancient horse, included detailed photogrammetry, capturing detailed photographs in an overlapping line that are then fed into a geographic information system (GIS).
The process allows specific measurements in a digitized 3-D map model of the trackways without physically disturbing or removing the ancient markings for further lab study. The process allowed three-dimensional measurements down to a half-millimeter, smaller than what can accurately be measured on-site.
For the July expedition, photogrammetry was conducted by a BLM team of experts, Brent Breithaupt and Neffra Matthews, who have documented tracks in the West since 1998. Also joining the team was James Martin from the University of Louisiana-Lafayette Geology Museum.
Through the work of passionate individuals curious of Oregon’s rich past, there now exists a greater understanding of ancient animals and landscapes that once dominated the area in the last great ice age.
It is just the latest in a massive array of secrets of the ancient world revealed thanks to a remote area of Oregon’s high desert.