The nation-shaping westward migration of about 500,000 people along the Oregon, Mormon and California trails began in 1843. Today, 175 years later — 106 years after the final documented wagon rolled down the trail in 1912 — evidence of their passage can still be found, etched into Wyoming’s arid soils.
But it won’t last forever. The sage is slowly returning and the wind is eroding the wagons’ wheelprints. One day the ruts will fade to invisibility.
“It is inevitable that they will disappear with time,” said Dana Pertermann, an associate professor of anthropology and geology at Western Wyoming Community College.
So Pertermann is studying and documenting the ruts across Wyoming while she can.
This summer, Pertermann will use photography, ground penetrating radar, a magnetometer and an electromagnetic resistivity system — the same tools she’s using to look for unmarked graves along the Oregon Trail — to digitally document the ruts.
“I want to digitize the Oregon Trail,” she said.
She’ll focus her efforts this summer on the South Pass area, but in the next few years would like to document the length of the trail in Wyoming, she said.
Much of the Oregon Trail has already disappeared. The ruts left behind in some places have already faded according to photographs Pertermann has seen from the 1960s. But many stretches of ruts in Wyoming remain distinctive, Pertermann said. The trail’s best remaining ruts are found in the state.
The ruts near South Pass look at times like a two-track road winding through the sage. The hundreds of wagons running over the landscape compacted the soil so much it was hard for vegetation to grow again, said Krystal Hazen an archaeologist with the Bureau of Land Management. How distinctive the ruts remain depends on the soil type and amount of use they see from vehicles, trekkers or livestock.
The arid environment at South Pass also helped preserve the ruts, said Curtis Bryan, an assistant field manager for resources with the BLM’s Lander office.
Erosion is slower there thanks to minimal rain and plant growth. Vegetation could one day fill in the tracks cut by the wagons, but when that day might come is hard to predict, he said.
The BLM monitors a stretch of the Oregon Trail frequented by members of the Church of Jesus Christ of Latter-Day Saints who trek portions of the Mormon trail. That portion of the trail is very defined because it sees so much use, he said. There haven’t been signs of significant erosion of the ruts, which they monitor annually, in more than 15 years, he said.
Bryan expects someday the BLM will be able to take aerial photos that could show with a high level of accuracy the soil loss in those areas and how quickly the ruts are eroding.
Wyoming’s ruts are unique, Hazen said. In other states the Oregon Trail crossed what is now private land that has been developed and farmed. Wyoming has the largest intact portion of the Oregon Trail remaining, she said.
But what really makes Wyoming’s stretch of trail special is the view. The Oregon Trail stretches across a landscape that is nearly identical to what the pioneers would have seen. The BLM has protected the views along with the trail.
“You can stand on the Oregon Trail and have expanses that follow the trail out to the horizon line,” Hazen said.
That sense of history is what inspired Pertermann to document the ruts. Pertermann doesn’t know when the ruts will disappear, but she wants to make sure the data has been collected before they do.
The images she plans to collect will allow her to look for patterns in the ruts and also might help predict erosion.
The erasure of the 2,000 mile Oregon Trail is “a process that is happening,” she said. “It’s not a process that is going to happen and we’re not doing enough about it.”
ED NOTE: This story has been changed to correct Krystal Hazen’s name.