Mules on the Moon: Unlikely Partners in Sagebrush Restoration Carry Their Weight

By Clara Deforest Colvig, January 2025

Efforts to restore shrinking sagebrush ecosystems are underway at Craters of the Moon National Monument and Preserve (the park). Along Idaho’s U.S. Highway 26, National Park Service (NPS) ecologists are enhancing the efficiency of sagebrush restoration and teaming up with a long-time partner of mankind: the mule.

For centuries, mules have been used to haul heavy loads and assist with industrialization, and since 1899, they have been deemed the mascot of the United States Military Academy. In ancient times, mules were ridden by kings and military generals. Mules even appear in the writings of Aristotle. Today, at the park, the pack animal can now add conservationists to the resume.

To remove cheatgrass more efficiently, scientists have begun using mules.

NPS Photo

Teaming Up for Restoration

Getting rid of sagebrush can be a grueling task, especially when trekking through the rough, lava-filled terrain of Idaho with liquid herbicide strapped to one’s back, which is generally how it’s been done in the past. As beasts of burden, however, mules are well-equipped for the demands of this job.

Biologically, mules are a cross between a male donkey and a female horse. They exhibit a phenomenon known as hybrid vigor. This means offspring are often healthier, stronger, bigger, and more intelligent than their parents, making them the perfect steed for tough jobs.

As one of the most imperiled landscapes in North America, occupying only 50 percent of its historic range, sagebrush is threatened by an accelerating cycle of weed invasion, wildfire, and drought.

It is a culturally important landscape to Indigenous tribes and United States history in general.

Native Americans have relied on the sagebrush habitat as an important food and medicinal source. For example, biscuit root and pinyon pine have historically been harvested from sagebrush ecosystems by Native tribes and families. This practice continues today.

At Craters of the Moon, an essential first step in sagebrush restoration is to remove cheatgrass, an annual invasive species grass that outcompetes native plants in the sagebrush biome, causing habitat degradation and increased wildfire risk.

For the first phase of the work, mules were able to carry 24 gallons of herbicide and helped spray about 200 acres in three and a half days.

“Based on our calculation, it would’ve taken four people 16 days on foot to do the same work,” said Linda Manning, chief of natural resources management at the park.

NPS contracted with a vegetation management service based in Declo, Idaho skilled in environmental management techniques for targeting specific invasive species across acres of public lands. The small business uses mules to carry larger loads of herbicide and travel longer distances more efficiently than any human could.

“Our restoration projects have always been kind of small scale because they are so labor intensive,” said Manning. With the mules, the NPS can now restore sagebrush more efficiently, cost effectively, and on a larger scale.

Healthy sagebrush in Craters of the Moon National Park and Preserve.

NPS Photo

The Bigger Picture

The sagebrush restoration project will help to protect a landscape that has both important natural and cultural resources.

NPS Photo

Restoration work with the mules began in September 2024 and was monitored throughout the year. The effort is part of a broader, multi-park initiative called NPSage that works to conserve and restore sagebrush ecosystems, bolster their resiliency, and increase their biodiversity.

“Through that initiative, we identified high priority park lands or landscapes that were most important to invest in,” said Tom Rodhouse, an NPS ecologist specializing in sagebrush. “As far as the Park Service’s contribution to the broader strategy to defend and grow the core of the sagebrush biome, Craters of the Moon is the place. The amount of healthy sagebrush land there is greater than what we have in all our other parks combined.”

Rodhouse explained that due to this ecosystem’s natural dryness, planting native species can be difficult. The new plants require a lot of water to ensure they take hold to the land. So, in a similar fashion, mules may aid in carrying water to staff working in the field.

Using mules has helped advance restoration that could potentially be a career-long or life-long project, Rodhouse said.

“We were delighted to get things moving and thrilled when we realized this was possible with mules,” he added.

Clara Deforest Colvig
Clara Deforest Colvig is a recent graduate from Colorado State University. She works in the National Park Service’s Natural Resource Stewardship & Science Directorate through a Conservation Legacy individual placement.