From Epitaph Issue 11, Published March 9, 2007

For more than 50 years, scientists from the U.S. Department of Agriculture have studied the area around Tombstone so they can better understand ecological issues in the desert.

USDA scientists’ goal is “to develop knowledge and technology to conserve water and soil in semi-arid lands.”

The project area is a 93 square mile region called the Walnut Gulch Experimental Watershed, which surrounds Tombstone and reaches south into Mexico.

Dr. Mark Nearing, research leader at the USDA-run Southwest Watershed Research center says the length of the ongoing project is “intentional and important, because its critical that we establish trends.”

These trends are tracked using data the scientists have collected over the years and help scientists to figure out how the desert is changing. For example, heavy droughts in the past decade have changed the area’s vegetation.

This data help scientists format public policy to preserve desert lands.

The research benefits residents because scientists can identify and study environmental issues before they become big problems. The scientists also work hand-in-hand with the community.
“We try to understand what the ranchers’ problems are,” Nearing said.

Finding vegetation to feed cattle and making sure there is enough water are among the ranchers’ top priorities, Nearing said.

A large issue with a direct affect on the entire Tombstone population is making sure there is enough water to keep up with population growth and ranchers’ needs.

This is an issue concerning Betty Krug, a long-time area resident.

“If they keep developing the desert, we are going to run out of water,” Krug said. “We need wiser use of water. People think it comes from everywhere.”

The original reason this project was established in 1954 was to study the effects of water conservation efforts upstream on the San Pedro River Basin, to see how they affected water users downstream.

There had been conflicts between landowners who were worried about upstream water users hoarding water. The downstream landowners wanted to make sure there was enough for them too. The U.S. government wanted scientists to study this problem to decide how public policies could end these conflicts.

The project started with $225,000 from the USDA. The breadth of research has greatly expanded since then.

The project has eight scientists who work with University of Arizona students on a $3 million annual budget funded through the USDA.

Current projects fall under four main categories: erosion and sedimentation, hydrology, creating computer models to help make policy decisions, and using remote sensing technology like satellites.

Over the past half-century, experiments have contributed to producing the world’s largest rangeland hydrology and erosion database.

The scientists have one of the largest published collections of satellite observations combined with ground observations in the world, and their research has contributed to water harvesting technology used worldwide.

“Erosion rates, relative to most rangeland in the United States are very high,” said Nearing of why the scientists’ research is important to Tombstone residents. “There has been a loss of capacity.”

This means area ranchers are having a harder time finding plants for their cattle to forage.

“The land was beat up pretty bad because of mining and heavy ranching in the 1800s,” Nearing said. He added that, “The ranchers need to have support. If the perception is that there is no problem, they are unlikely to get the financial support they need from the federal government.”

Ranchers aren’t the only ones concerned about erosion. Teresa Benjamin, a Boot Hill Cemetery employee, worries about monsoons because of earth erosion.

After a rainstorm, she can see damage to the graves. She said most of them are covered with rocks now to keep the graves from washing away.

The area, problems and technology are always changing, said Mary Nichols, a research hydrologic engineer and member of the scientist team working near Tombstone.

“Keeping science moving fast enough to respond to people’s impacts of the area” is one of the challenges of the future, Nicols said.

“We need to stay current,” she said.