Wop May, the Mad Trapper of Rat River, and the Winter Manhunt That Put a Bush Plane at the Center of the Most Desperate Chase in Canadian History

In the winter of 1932, a 48-day manhunt across the Canadian subarctic produced something no one expected: the birth of aerial search-and-rescue doctrine. Bush pilot Wilfrid “Wop” May, flying a Bellanca Pacemaker over frozen river bars and mountain ridges in temperatures approaching fifty below zero Fahrenheit, demonstrated for the first time that an aircraft could function as intelligence - not just transportation. The techniques he improvised during the hunt for Albert Johnson, the “Mad Trapper of Rat River,” became the template for every aerial search that followed.

Albert Johnson and the Rat River Incident

A man calling himself Albert Johnson appeared in the Mackenzie River Delta region of Canada’s Northwest Territories in the summer of 1931. He built a trapping cabin on the Rat River, where it descends from the Richardson Mountains toward the delta, and made no effort to explain himself or integrate with the surrounding community.

Reports soon reached the Royal Canadian Mounted Police that someone was raiding Inuit trap lines - springing sets and taking the catch. Constable Alfred King traveled to the cabin in late December 1931 with a guide and knocked. Smoke was rising from the chimney. Johnson was inside. He didn’t answer.

King returned days later with a warrant and additional men. When he called out again, Johnson answered by shooting through the door. King took a round in the chest. He survived, but only through extraordinary effort by his partner to get him back to a settlement alive.

The Siege at the Rat River Cabin

The RCMP returned with nine officers and dynamite. They surrounded the cabin. Johnson refused to come out. When they threw explosive charges against the walls, the structure partially collapsed around him.

He kept shooting.

One man, inside a half-demolished cabin, in the dead of a sub-Arctic winter, held off nine officers for hours. When he finally went quiet and they moved in, there was no body. Johnson had slipped into the darkness and disappeared into the bush. The temperature that night was approximately fifty below zero Fahrenheit.

48 Days That Became Legend

What followed was forty-eight days that entered Canadian history. The RCMP brought in experienced dog teams and some of the most capable outdoorsmen in the North - hunters, guides, and trappers who had spent their careers in that country.

Johnson had a more sophisticated evasion strategy than anything they had encountered. He would walk a straight line for miles, backtrack by stepping precisely in his own prints, then jump sideways onto hard wind crust that left no impression. Trails ended in empty air. He strung traps across his own back trail - the kind designed to remove an animal’s leg - catching officers following him in the long Arctic dark.

In mid-January, Constable Edgar Millen, an experienced and respected officer who had served that country for years, caught up to Johnson in a ravine. Johnson killed him.

Reinforcements arrived from across the region: more dog teams, more officers, civilian volunteers who knew the terrain. The weather worked against everyone - temperatures that killed sled dogs, storms that obliterated tracks overnight, and days that offered perhaps five hours of usable light if the sky cooperated. Johnson was still winning.

Why the RCMP Called Wop May

Wilfrid Reid “Wop” May - the nickname came from a younger relative who couldn’t pronounce “Wilfrid,” and it stuck for life - had been operating with Commercial Airways out of Edmonton and had spent years learning the North: its weather patterns, its terrain, and the behavior of aircraft at temperatures where most people abandoned numbers and sought shelter.

He was also one of the more fortunate young pilots to emerge from the First World War. On April 21, 1918, on just his second combat flight over France, he found himself being pursued by Manfred von Richthofen - the Red Baron, 63 kills to his name, looking for his sixty-fourth. May did what a green pilot could do: he dove for the deck, followed the Somme River at treetop level, and ran. While Richthofen was fixed on the chase, Captain Roy Brown from above and Australian ground gunners below brought the Red Baron down. May climbed away and lived.

He spent the rest of his life flying.

By the time the RCMP reached out in late January, May had the experience and judgment the situation required. He brought a Bellanca Pacemaker - a high-wing monoplane with a radial engine, built for range, load capacity, and the ability to set down on a frozen river bar and get back up again - into the Aklavik area.

Aircraft as Eyes: A New Kind of Search

The conditions May operated in were extreme even by bush flying standards. Fuel gelled. Oil behaved like something that had changed states of matter. At altitude, with the wind of his own airspeed compounding ambient temperatures, a cockpit failure out over that wilderness left a pilot in the same position as the men below - except also with a wrecked airplane to deal with.

May flew anyway. Every day the weather allowed. And some days it probably shouldn’t have.

What he was doing had never quite been done before in a North American manhunt. He dropped supplies to ground parties running short. He flew reconnaissance over country ahead of the search teams. From altitude, over white terrain in winter, a man’s track across open ground stands out like a pencil line on white paper. May could cover in one hour what a dog team needed a full day to cross. He would spot the direction of travel, radio it back, and ground parties could reposition - cutting off approaches, pushing Johnson where they wanted him.

Aircraft as eyes. Aircraft as intelligence. Not a truck with wings, but a way of seeing the country that no one on the ground could match.

Johnson Crosses the Richardson Mountains

Then Albert Johnson did something that stopped everyone cold.

In February, on snowshoes, alone, he crossed the Richardson Mountains.

The passes fill with snow in February. The winds coming over the ridgelines can take a man off his feet. The experienced woodsmen tracking Johnson said flatly that it could not be done - not without a dog team, not without cached supplies, not by one man on foot.

Johnson crossed them anyway and came down the other side into the Yukon.

When May flew over the divide and picked up the track line on the far side, the accounts from that time carry a palpable shift in tone. Everyone involved understood they were dealing with something genuinely extraordinary - not a desperate man stumbling through on luck, but someone operating at the absolute edge of what a human being can physically do in that environment, doing it deliberately, with discipline, with a plan.

But the crossing had cost time and left Johnson exposed on open snow. From altitude, May could see the track clearly. The ground parties could close the gap.

February 17, 1932: The Eagle River

On February 17, 1932, Johnson was moving along the Eagle River when the lead party caught him in the open. There was a firefight. Johnson wounded two more men before he finally went down.

When they examined what he was carrying, they found a careful, well-maintained kit: gold dust, money, equipment packed by someone who had planned for a very long stay in the backcountry. Nothing with a name, a hometown, or a past.

An Identity Never Confirmed

Nobody has ever confirmed who Albert Johnson actually was.

DNA analysis in 2007 produced possible relatives in Norway, but the connection was never confirmed. Decades of archival research have generated theories - a bank robber, a man wanted for violence south of the border - but no verified identity. The name Albert Johnson sits over his grave in Aklavik, and whether that was his actual name remains unknown.

What Wop May’s Winter Changed

Before those forty-eight days, a bush plane was defined by what it could carry and where it could take it. After, the understanding shifted.

People saw that an aircraft was eyes - that from altitude, over white country in winter, you could see what no ground party would ever see. That you could cover distances that defeated dog teams. That you could locate a man, radio his position, and change the entire shape of a search.

Every aerial search pattern that developed in the years after has some lineage to what May was doing over those river bars and mountain ridges. Every grid pattern flown by Civil Air Patrol volunteers. Every backcountry search that begins with an aircraft overhead. The template was written in real time, during the coldest weeks of 1932, by one pilot who had no procedure manual - only an airplane, a radio, and the judgment that comes from years of reading the world from altitude.

Wop May died in 1952, having lived long enough to see the routes he helped pioneer become the commercial air network connecting Canada’s North to the south. He trained pilots, advocated for remote community infrastructure, and watched aviation transform into something unrecognizable from the honest, muscular machines of his era.

The winter of 1932 is where the larger story of aerial search-and-rescue begins.

Further reading: Dick North’s The Mad Trapper of Rat River is the definitive account. Primary source records are available through Library and Archives Canada via the RCMP’s historical files.

Key Takeaways

• Albert Johnson arrived in Canada’s Northwest Territories in the summer of 1931, built a cabin on the Rat River, survived a nine-man armed assault, and evaded into the wilderness at temperatures near fifty below zero Fahrenheit.
• A 48-day manhunt - during which Johnson killed Constable Edgar Millen and wounded several other officers - ended on February 17, 1932, on the Eagle River in the Yukon.
• Johnson’s solo crossing of the Richardson Mountains in February, on snowshoes, was considered impossible by the experienced woodsmen pursuing him.
• Wop May, flying a Bellanca Pacemaker from late January 1932, pioneered the use of aircraft for visual tracking, radio-coordinated positioning, and supply drops to ground teams - the first documented use of these techniques in a North American manhunt.
• Johnson’s identity was never confirmed; DNA work in 2007 suggested possible Norwegian ancestry but produced no verified connection.