Don Rosenberry has returned to the same isolated, muddy lake several times a year for the past 40 years.

A hydrologist with the U.S. Geological Survey, he studies the properties and movement of water.

He's spent his career at Shingobee Lake. It's about three hours northwest of the Twin Cities, near Walker, Minnesota.

One of Rosenberry's old bosses had a explanation for why someone might keep coming back to the same spot for research: "He had a saying: 'You have to study a place for a while before you begin to ask the right questions,'" Rosenberry recalled.

Rosenberry has spent decades trying to ask the right questions about Shingobee Lake. At 40 years old, the research at Shingobee has become one of the longest continuing projects in the nation that shows how an entire watershed is impacted by climate change.

But the future of all that research hangs in limbo. The Shingobee research station's funding might be cut off in the next USGS budget year, as the agency's finances stagnate.

Science at Shingobee has changed, and so has the climate

Rosenberry first came to Shingobee as an undergraduate student at Bemidji State University in the late 1970s.

"Someone came into a soil science class and asked if anyone from the Walker area might be interested in a part-time job," he said.

Don Rosenberry, a hydrologist with the U.S. Geological Survey. Alex Baumhardt for MPR News

The job was related to studying groundwater. That's what scientists were doing at Shingobee then.

But the research grew over the following decades, and a diverse set of scientists from different fields began studying the entire watershed.

"We were looking at climate change issues much before the big issues related to climate change became more publicly known," Roseberry said.

At Shingobee, researchers measure how the lake responds to frequent periods of drought and heavy rain, evaporation, and warming lake bottom temperatures.

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They've even noted changing animal populations, like the decline of snowshoe hares and the rise of the gray fox.

Money struggles at the USGS

Over that time, the USGS budget has become tight. It's lower today than it was 10 years ago, accounting for inflation.

And for its next budget year, funding to keep Shingobee open is uncertain. USGS says it's trying to partner with other organizations, like universities or nonprofits, to take over funding of the Shingobee field station, which costs $20,000 per year to maintain.

"That's just how tight things are," Rosenberry said. "It's gotten so bad we're looking at amounts even as small as $20,000."

He has heard they have until Oct. 1 to figure it out.

Last year, USGS was one of several agencies within the Department of the Interior that was restructured.

The USGS National Research Program, which was tasked with water research, was disbanded. The agency reassigned National Research Program scientists like Rosenberry, but kept alive their research projects.

Rosenberry is hopeful he can keep the work at Shingobee alive, and that scientists there can continue to provide decades more research and context to our understanding of how lakes respond to a changing climate.

After 40 years, Rosenberry thinks he and other scientists are finally beginning to ask the right questions that his old boss told them they needed time to ask.

"I would say if we stop now we won't be able to see what happens as these changes progress," he said. "We'll basically stop the study right in the middle of the really exciting part."

Alex Baumhardt is a producer for APM Reports. This reporting was made possible with help from the Institute for Journalism and Natural Resources.