Every now and then a piece of work comes along that honestly earns the title “game changer.”

When it comes to understanding the importance of western landscape habitats for big game conservation, the Wyoming Migration Initiative has moved into that realm.

Last week this multi-agency effort headquartered at the University of Wyoming proved mule deer populations in western Wyoming undertake an annual a 150-mile migration between summer and winter ranges.

A data-rich report and an amazing video show this population of thousands of mule deer making its way from wintering range in the Red Desert to its summer range in the mountains south of Jackson.

The report is something of a shock, because this epic annual event by some very large and numerous animals apparently has been taking place undetected for generations.

But it’s a game-changer because we now know that mule deer, instead of being homebodies who spend their lives in a limited habitat, are migrators that – like ducks and geese – need a variety of habitats over a larger landscape.

Just as we have long known waterfowl need uplands and seasonal wetlands as well as those larger permanent wetlands, we now know muleys not only need habitat protected from development in the desert and mountains, they also need safe and nourishing habitat along the entire migration corridor.

And that corridor currently finds them crossing three highways and more than 100 fences, as well as many reservoirs and rivers.

The study (and video) will be solid ammunition for conservationists battling what has often been a blind rush to develop of oil and gas in the same areas with little consideration to the impact on wildlife – and the substantial sport-hunting economy they support.

Just as removing wetlands in Missouri could impact ducks moving from nesting areas in the Dakotas to wintering grounds in Louisiana, chopping up migration corridors could have a profound effect on these animals.

The Theodore Roosevelt Conservation Partnership, which includes the Mule Deer Foundation, has been on this issue for years.

Ed Arnett, head of its Center for Responsible Energy Development, said the report reinforces many of its main points.

“If we do not safeguard all the pieces of that puzzle, including important habitats associated with migration, big-game populations likely will decline and impact both our outdoor traditions and our hunting-based Western economy,” he said.

If facts – and a video supporting them – mean anything, this report should be a game changer in this debate.

Mule Deer Migration from Joe Riis Photography on Vimeo.