An Idaho helicopter crew trained to net big-game animals for wildlife research is aloft in southeastern Minnesota this week on a mission to capture 115 whitetail deer for the Department of Natural Resources.

Paired with ground workers who release the deer after collaring them with GPS devices, Hells Canyon Helicopters is creating the framework for a study that will map deer movements to understand where chronic wasting disease (CWD) could spread. The $450,000 research project will last for more than two years to sharpen the DNR's ability to fight the state's largest outbreak ever of CWD.

"We're trying to determine potential prion disease pathways,'' said Lou Cornicelli, DNR wildlife research manager.

As of Tuesday afternoon, at least 32 deer had been fitted with battery-powered Lotek LiteTrack expandable GPS collars. Cornicelli said the capture work is behind schedule in part because a Hells Canyon helicopter crashed in late January out west, killing one of three crew members.

The 19-year-old man who died, Benjamin M. Poirier, was on assignment to capture mule deer in the Blue Mountains for the Washington Department of Fish & Wildlife. Two weeks later in Utah, another flight company experienced a crash when an elk jumped into the tail rotor of a low-flying helicopter. No crew members were killed.

"It's dangerous work,'' Cornicelli said. "That's what kind of gets lost on a lot of people.''

The Minnesota contract with Hells Canyon included the capture of 19 whitetails in northern Minnesota for a separate GPS tracking study. In that research, headed by Glenn DelGiudice of the DNR, the agency is trying to understand more precisely where the animals go in winter for food and cover.

Ideally, highly accurate location data will allow the DNR to draw up "prescriptions'' of habitat needs that can be shared with forest managers, DelGiudice said. The information — especially critical for severe winters — would boost the state's deer management efforts, he said.

The northern capture effort was completed March 10 and 11, but a cracked windshield on the helicopter had to be repaired before flights could begin in southeastern Minnesota. Hells Canyon's Robinson R44 finally lifted off Sunday from the airport in Rushford, capturing 18 whitetails the first day.

"Slowly but surely we're catching deer,'' DNR research scientist Chris Jennelle said Tuesday. "But there's a concern we might not reach our goal.''

Cornicelli said the plan was for flights to begin in the southeast in February, when deer are bunched up and easier to find on snow-covered ground. Starting in April, young deer — especially males — disperse from their homes. Those are the animals most sought by the DNR for collaring.

"We will focus on yearling deer because they are the most likely to disperse to new areas,'' the DNR wrote in its study proposal to the Legislative-Citizen Commission on Minnesota Resources.

The GPS collar location data, received daily by the research staff, will be used to create a predictive deer movement map to educate DNR on where to establish disease surveillance. The collars are good for two to three years, and the agency already has planned to collar more deer in 2019. Ideally, the study in southeast Minnesota would look at the movements of nearly 150 deer, including some adult males because bucks are three times as likely as female deer to carry CWD.

Hunters should not hesitate to shoot a collared deer during hunting season, Cornicelli said. Part of the study will examine causes of mortality. The GPS collars will alert the DNR when a death is suspected. The collar can be reused, and the DNR encourages hunters to turn them in.

"We want hunters to treat collared deer like any other deer,'' he said.

Southeastern Minnesota's CWD outbreak in wild deer was detected in 2016 between Lanesboro and Preston during routine surveillance of the deer season. In the past two years, 17 positives have been found in the same zone that encompasses Fillmore County and some surrounding land. It's now known as CWD Management Area 603.

The DNR has been racing to combat the outbreak because scientists believe it was detected early enough to possibly stop it. Wisconsin and Iowa are faced with intractable CWD outbreaks, and Wisconsin already is witnessing CWD deer deaths. The neurological disease always is fatal in deer and is similar to mad cow disease.

Minnesota's wild deer herd is estimated by the DNR to be a $500 million annual resource.

"A growing body of research suggests that in the long term, CWD causes deer population decline and has the potential to cross species barriers,'' the DNR said in a summary of its deer movement study.