He founded and nurtured Minnesota's non-game wildlife program in the same way he raised 4-H livestock as an Iowa farm kid.

In both pursuits, Carrol Henderson was creative, energetic and passionate. In fact, the first-year budget he was handed in 1977 by the state Department of Natural Resources wasn't worth much more than the muskrats he trapped as a boy, selling their fur to buy his first 4-H calves.

Now the distinguished bird watcher, hunter and expert taxidermist is preparing to leave the helm of what he developed into a $2.5 million-a-year conservation stronghold with 16 full-time employees around the state. He's the only DNR non-game wildlife supervisor Minnesota has ever known, and his projects over four decades have boosted the state's bald eagles, trumpeter swans, common loons, peregrine falcons, bluebirds, blue herons, egrets, sandhill cranes, purple martins, river otters, frogs, turtles, bats, ospreys and snakes.

When the 72-year-old Henderson retires in early October, he will leave a dynamic legacy.

"The man is like the Energizer bunny, and it's not nervous energy. The ideas just keep popping out of him," said Pam Perry, a retired DNR non-game wildlife biologist who lives in Brainerd.

Minnesota's acclaimed Raptor Center at the University of Minnesota might not exist if it weren't for Henderson. He's the person responsible for the state income tax Chickadee Checkoff, and he wrote five state-published conservation guide books that raised $250,000 in royalties for his own program.

The former Air Force captain has won at least three national conservation awards, including 2016's Frances K. Hutchinson Medal from the Garden Club of America. He's led 64 international bird-watching trips on his own time, including many to Costa Rica, the homeland of his wife, Ethelle. He once photographed two humpback whales off the coast of Costa Rica to help document their migration pattern. The images were used by the country's president to designate more than 13,500 acres of Pacific Ocean as a whale sanctuary.

Henderson championed pollinator habitat before it was popular and leveraged his outdoors credibility as a hunter of waterfowl, deer, pheasant and woodcock to fight against the use of toxic ammunition and lead fishing tackle. His field work that showed birds were feeding on lead shotgun pellets led to Minnesota's pioneering ban against lead shot for waterfowl hunting in 1987 — a shake-up that federal officials mimicked four years later.

In a couple of weeks, Henderson expects to cap his career with the announcement of a multimillion-dollar settlement from the 2010 Deepwater Horizon oil spill. He was at the center of a collaborative effort that showed pollution deficits to northern loons and white pelicans during their migration to the Gulf of Mexico.

The DNR wants a new non-game supervisor in place before Henderson leaves. When he's finished, a volunteer job awaits him as conservation program coordinator at the Minnesota Ornithologists' Union.

"Our feedback over the years was that our non-game wildlife program was the best in the country," said Tom Isley, a former DNR executive who encouraged the hiring of Henderson. "We could see Carrol as a visionary for non-game, and over the decades that proved to be true."

Henderson, who grew up on an idyllic, 132-acre family farm northeast of Ames, started his DNR career in 1974 as a traditional game manager at the Lac qui Parle Wildlife Management Area in Montevideo. It was his boss, Roger Holmes, who believed in starting a non-game wildlife program — in part to widen public support for the DNR.

Isley recalled there were critics of the initiative who disliked the DNR's divergence from hunting and fishing. But Henderson's bona fides as an outdoorsman, coupled with his rural sensibilities, blunted the criticism and helped get the program off the ground, Isley said.

"He grew up close to the land, and people respected that," Isley said.

Henderson said his first job in non-game wildlife was to find funding beyond his $25,000 salary to get things done.

"I was the supervisor of a statewide program in charge of nothing with no staff," he said.

Within four years the Legislature went along with his Chickadee Checkoff idea, an optional contribution to Henderson's program now augmented by proceeds from special license plate sales. Isley said it was Henderson himself who added the loon icon to the state tax return to highlight the checkoff.

Henderson was an effective collaborator throughout his DNR career, including major ventures with his friend Dr. Pat Redig, co-founder and former director of the Raptor Center. Together they captured 55 bald eagles from Minnesota's northern forests and gave them away to wildlife officials in New York, Missouri and three other states to boost eagle populations.

They also teamed up to initiate the Minnesota peregrine falcon restoration effort in 1981. The same year, Henderson wrote the initial Trumpeter Swan Restoration Plan for Minnesota, and they followed up with the largest-ever release of the birds (captured in Alaska). Today, the swan population includes more than 5,500 specimens across the state.

Redig said Henderson scratched for early, sustainable funding for the Raptor Center after politicians initially redirected funds that would have gone to the non-game wildlife program. The funding ingenuity by Henderson helped get the Raptor Center off the ground, independently, Redig said.

"He's a conniver in a good sort of way," Redig said of Henderson. "He pulls strings here, here and here and ties them together."

An early example was at Lac qui Parle, where Henderson raised $600 each from an outdoors club in Willmar, the Audubon Society and a state archery association to reintroduce river otters to southwestern and west-central Minnesota. The project paid northern trappers $150 per otter if they followed Henderson's special trapping instructions. It was an early success still visible in the Big Stone National Wildlife Refuge and elsewhere.

Perry said the DNR's hierarchy and myriad rules didn't dampen Henderson's ambitions. He stood behind his regional field staffers and encouraged them to be creative. Perry said Henderson once charged her with helping purple martin populations in the state without giving her a game plan.

"He just said, 'You'll come up with something,' " she recalled.

With continued encouragement, Perry worked with the Mille Lacs Band of Ojibwe on a successful habitat project for the swallows.

Henderson over the years also has facilitated the DNR's acquisition of more than 3,400 acres of wildlife lands. A memorable early gain was in 1982 when Henderson helped purchase more than 1,000 acres of woods, wetland and open water near Forest Lake. The land, including a blue heron rookery and ancient Indian burial mounds, had long been home to an exclusive private gun club. Henderson swooped in when heirs to the land were about to sell it to a mobile home park developer.

Today, the site near Interstate 35 is the Lamprey Pass Wildlife Management Area.

"It's been an absolutely incredible career," Henderson said.