Darren Troseth placed a death grip on his fishing rod for nearly two hours before strangers arrived to assist in landing a monster lake sturgeon that literally took their breath away.

On Saturday night on the St. Croix River near Bayport, Troseth and John Kimble went to their knees and bellies inside a cramped ice shelter to wrestle the massive fish onto the surface. More than half of the sturgeon was flat on the ice and snow, but at least 2 feet of it was still stuck in the hole.

"When I saw this thing my jaw dropped," said Troseth, 45, of Jordan. "To be honest, I didn't think we would get it."

Likely to go down as Minnesota's largest record fish of any kind, the ancient-looking sturgeon was 6 feet 6 inches long, 29 inches around and weighed an estimated 120 pounds. It's likely 60 to 70 years old. The Department of Natural Resources is verifying the catch, but Troseth has volunteered on DNR fisheries panels in the past and is well known at DNR headquarters as a sturgeon fanatic. He also documented the ordeal on video.

"I might be done ice fishing," Troseth said into the camera, laboring to catch his breath. "Honestly, I don't know if I want to experience that again."

The fish was not harmed and was released back into the river, Troseth said.

A part-time fishing guide in the summer months, Troseth said he's been targeting sturgeon this winter about once a week on the St. Croix for leisure. He hadn't caught anything in his previous five outings and he was waiting quietly with Kimble, a friend from Prior Lake, for three hours in their midriver location.

About 8 p.m., the stringy foam bobber on one of his two fishing lines quaked. It made just a tiny ripple, but Troseth was on alert because his sonar equipment had detected a big fish down below. His high-strength, braided line was set at bottom, rigged with a treble hook loaded with night crawlers and fathead minnows. The homemade lure included an egg-shaped sinker and beads of red, white and green.

With two hands on his full-sized, heavy-duty fishing pole, Troseth set the hook and reeled up. It felt like it weighed 100 pounds. That's when the fun began.

Within 15 minutes, the sturgeon was at the underside of the ice, two feet below the upper crust. But its head was too fat to fit inside the double-sized hole that Troseth drilled during setup. Troseth and Kimble struggled with a malfunctioning drill to widen the hole, but the opening was still too narrow to accommodate the sturgeon. By now, Troseth's back was sore. When the fish struggled, the line would sometimes cut into the ice and he worried it would break.

On Facebook, Troseth and Kimble belong to a fishing group called Minnesota Sturgeon Fishing. Anglers in the group often congregate on the St. Croix, and screen time is a pastime when the action is slow. Troseth pinged the Facebook page with an SOS to anyone nearby who could widen the hole.

"We described our general location and flashed a light in the air," he said.

Their prayers were answered when two strangers drove up to their pop-up ice shelter in a pickup truck. Using an auger, they carefully widened the hole to about the size of a trash can lid. Troseth worried that the blade would accidentally cut his line. At one point during the process, he stumbled backward and submerged one of his legs inside another fishing hole.

When it was time to hoist up the sturgeon, Kimble dropped to his stomach in the snow and slush. He was wet to his shoulder, reaching around the fish's head for anything to grasp. His fingers landed in a divot under the fish's nose and he pulled up until the sturgeon was visible above the ice.

"We grabbed the whole head and slid it out," Troseth said.

In the video, at least four people are laughing as Troseth pushes a chair out of the way to make room for the fish.

"Oh my god, that's nuts," someone says. "That thing is bigger than you!"

The existing Minnesota catch-and-release sturgeon record was set within the past two years on Rainy River with a fish that was 73 inches long. The weight estimate for Troseth's 78-incher was derived from a DNR chart that estimates poundage based on fish length and girth.

DNR Fisheries Chief Brad Parsons said the certification of Troseth's fish is pending, but there's no apparent hangup.

"It doesn't surprise me," Parsons said. "He knows how to fish sturgeon."

Tony Kennedy • 612-673-4213