A Yukon deputy judge has accepted the guilty pleas of a Winnipeg man whose driving caused a 2020 crash near Marsh Lake, Yukon, that killed two people — including the man's girlfriend and a Whitehorse motorcyclist — and left another injured.

Devin Edmiston pleaded guilty to two counts of dangerous operation causing death and one count of dangerous operation causing bodily harm last November, but a disagreement between the Crown and defence on key facts prevented the case from moving ahead.

The dispute was settled on March 3 with both sides filing a joint admissions-of-fact document in Yukon Territorial Court before deputy judge Gurmail Gill, who then formally accepted Edmiston's pleas.

According to the admissions, Edmiston, then 25, and Nicole Sanderson, his 47-year-old girlfriend, drove from Manitoba to Whitehorse in June 2020 to visit her family and friends.

The couple, along with four of Sanderson's family members, decided to visit Army Beach, about 45 kilometres southeast of Whitehorse on Marsh Lake, on July 5, 2020, leaving from Whitehorse's Riverdale neighbourhood in two cars.

Edmiston, the admissions say, drove Sanderson's 2003 Oldsmobile Alero sedan, with Sanderson in the backseat and the father of Sanderson's grandson in the front passenger seat. The rest of the family, including two of Sanderson's daughters and her grandson, travelled in a 2010 Chevrolet SUV.

No one in Sanderson's car, according to the admissions, wore their seatbelts, and Edmiston did not have a driver's licence — nor had he ever held one.

With the SUV leading the way, the vehicles travelled down the Alaska Highway, heading southeast toward Marsh Lake.

The highway begins to curve near the bridge by the Lewes River dam, with double and solid yellow lines indicating it's a no-passing zone; it was there, according to the admissions, that Edmiston began accelerating and moved the car into the oncoming lane in an attempt to overtake the SUV.

The SUV, the admissions say, was travelling at a range of 135 to 147 km/h; Edmiston's male passenger "became uncomfortable and voiced his concerns," but Edmiston didn't hear him.

As Edmiston was attempting to pass, two oncoming vehicles came over the hill. Both "took action" to avoid colliding with the sedan, the admissions say, and Edmiston attempted to move his car back into the southeast lane. However, he hadn't fully overtaken the SUV yet and the rear passenger side of the car collided with the SUV's front driver's side door.

Edmiston lost control of the car, which spun and skidded across the highway before colliding with an oncoming motorcycle driven by 43-year-old Travis Adams of Whitehorse.

Adams was killed on impact.

The car then rolled and came to a rest, "extensively damaged," off the shoulder of the highway, the admissions say. Sanderson was severely injured and died on-scene, while the male passenger suffered serious injuries including a fractured sternum and spine damage.

Edmiston himself suffered bruising to his face and a fracture to his upper jaw. The occupants of the SUV, which went into the ditch, were uninjured.

Adams' family, including his wife and three children, were travelling in a car "some distance behind" his motorcycle, according to the admissions, and soon arrived at the scene.

Edmiston was treated at Whitehorse General Hospital before returning to Manitoba, where he was arrested and charged in relation to the crash — which the admissions say was not caused by any impairment or mechanical failure — on May 4, 2021.

Two months before the crash, Edmiston had been stopped while driving by police in Manitoba and was issued tickets for speed and driving an unregistered vehicle, the admissions say.

"Mr. Edmiston admits that his driving pattern on Sunday, July 5th, 2020, demonstrates conduct amounting to a marked departure from the standard of care that a reasonable person would observe in his situation and that his conduct meets the legal threshold for criminal liability," the document concludes.

"Mr. Edmiston also admits that his drive pattern caused the deaths of Mr. Adams and Ms. Sanderson, and bodily harm to [his passenger]."

Edmiston's sentencing hearing is scheduled to begin May 17.