After three decades in Congress, Collin Peterson's life's work is now stashed away in 150 boxes.

Packing up the dead animal heads, old letters and plaques in his Washington, D.C., office reminded Peterson of little things even he'd forgotten after so many years, like the framed bill he saved more than two decades ago when he proposed to cede Minnesota's Northwest Angle to Canada.

It never happened, of course, but that wasn't the point. The bill was a publicity stunt to bring attention to an across-border walleye dispute in his district, and it worked. Ontario backed off catch restrictions they imposed on his constituents.

"I did my duty and I didn't get in a whole lot of trouble," Peterson, 76, told the Star Tribune in one of his first interviews since the former DFL lawmaker lost his race for re-election to Republican Michelle Fischbach. "None of what I accomplished is going to be earth shattering for the whole nation, but some of the things I did were a big deal in my part of the world."

His part of the world means the rural counties, cities and townships that make up the sprawling Seventh District of Minnesota bordering the Dakotas, which he represented in Congress from 1991 until January. Peterson's departure marks the end of an era: The founding Blue Dog Coalition member was one of the last conservative Democrats left standing in an increasingly polarized Congress. In his role as chairman of the House Agriculture Committee, he left an indelible mark on state and national policy.

"Collin was a giant in Congress. I think it's going to take years for Minnesota to fully understand what a huge loss it is not having the [agriculture] committee chair being someone from here," said Second District Rep. Angie Craig, for whom Peterson became an unlikely mentor. "It surprised some people that this 30-year veteran member of Congress and this lesbian mother from Eagan developed a great working relationship, but Collin taught me a lot and he showed me how important it is to continue to try and find common ground."

In his nearly 40-year career in politics, including a decade in the state Senate, Peterson made the most headlines for breaking from his party in places where rank-breakers are a dying breed.

Peterson supported Bush-era Republican tax cuts. He didn't vote for the Affordable Care Act, but he opposed GOP efforts to repeal it. He opposed abortion and supported gun rights, the only Democrat in the last election cycle to get an A-rating from the National Rifle Association.

Peterson voted against both articles to impeach Donald Trump the first time around — one of only two Democrats to vote no — but he said he would have voted to impeach Trump this time after a violent mob breached the U.S. Capitol on Jan. 6. "Something has to be done. You don't let this thing go," he said. "Clearly the president stirred these people up. You can't deny it."

But most of the things he packed away in boxes had to do with his decades of work on the House Agriculture Committee, including two stints as chairman. He's got documents from the 1996, the 2002 and the 2008 farm bill, which he sponsored and passed despite a presidential veto. In 2018, Peterson played an instrumental role in negotiating a farm bill nearly sidelined by Republican insistence on strict food stamp restrictions.

National Farmers Union President Rob Larew, who spent years working for Peterson, described him as a voracious reader who traveled all over the country to understand the challenges facing farmers in different regions.

"Even though I tried constantly to stay on my toes, he was always one step ahead of me," said Larew, who noted that that style translated to Peterson's news conferences, which never followed the prescribed talking points. "He's not thinking through how to phrase things in a way that come across the best, or what's going to be picked up most immediately, or what's a clever turn of phrase, he's going to tell it like it is," he said. "It always made me nervous as a staffer, but it was also refreshing."

Peterson's political and personal style — he flew a single-engine plane to get around and played in a cover band called the Second Amendments — helped him survive multiple Republican waves in his conservative district. After 2016, he held the distinction as the Democrat who represented the district that swung the hardest for Trump, by 31 points.

But with Trump back on the ballot last fall, Republicans recruited Fischbach, a former state senator, and flooded the district with attack ads. Peterson lost by 14 points. "I think it was mostly Trump and all the money they spent, and they didn't tell the truth [about my record]," Peterson said. "If you tell a lie long enough, sometimes people start to believe it."

Congress is too polarized for him to ever go back, he said. Instead, he's excited to spend more time with his three sons and his grandchildren. People in the grocery store still ask him to help with their issues in Congress, which he gently reminds them isn't his job anymore.

His old constituents in the Northwest Angle are also calling again as the border between the U.S. and Canada remains closed during the pandemic. Their request for help with the walleye dispute started two decades ago with a request for Peterson to lie on the railroad tracks in protest. "They are back to wanting [me] to lay down in the railroad tracks again," he said.

He's had plenty of job offers since he's left, but there's one the former agriculture chairman is considering more than others: selling farm equipment. "I'm thinking about doing that. When I tell people that, I get this silence," he laughed. "This is a way to stay involved in agriculture that is totally different from anything I've ever done, which has some appeal."

Peterson's also been busy lately helping the Becker County Museum with a massive project to digitize all of his work and recreate his Washington office in his hometown of Detroit Lakes. He bought his desk and his chair from the U.S. House and sent those 150 boxes to a climate-controlled room, where a retired history teacher plans to sort through it all. He even donated some of his remaining campaign cash to help get the project off the ground.

"That's the sort of thing that usually goes to a larger entity," said Becky Mitchell, executive director at the museum. She thinks the exhibit will be a "huge draw" in the area.

It's a good deal for Peterson, too, who now has a backup plan if he fails at selling farm equipment.

"If I get bored," he said, "I can go down and sit in my old office and just hang out."

Briana Bierschbach • 651-925-5042

Twitter: @bbierschbach