Eric Jahn drove his boat to an open stretch of water in the middle of Lake Granby in north-central Colorado and cut the motor.

The jagged ridge line of the nearby mountains loomed in the horizon. But there were few landmarks on shore to show Jahn he was in the right spot.

That’s where his electronics came into play. The depth finder on the dash of his boat showed that it was more than 80 feet deep here. And that, Jahn said, was a perfect place to fish for Granby’s abundant lake trout.

“Someone who isn’t familiar with this lake would go right past a place like this,” Jahn said as he readied the rods. “It just looks like open water.

“But there’s a hole here, and that’s what these lake trout like. Water temperature is the key. It’s not unusual for us to fish in 70 to 80 feet of water for these lake trout.”

In other words, a lot deeper than most freshwater fishermen have ever dropped their lines.

“A lot of flatlanders can’t believe how deep we’re fishing,” said Jahn, who guides for Beacon Marina on the scenic 7,000-acre lake. “But that’s where the fish are.”

Jon Ewert, who manages the Lake for the Colorado Wildlife and Parks Department, agreed. He said lake trout can go as deep as 100 feet in the summer months.

“They want water where the temperature stays below 60 degrees,” he said. “They can easily go 100 feet deep.”

The screen on Jahn’s fish finder indicated as much. It was speckled with lake trout holding near the bottom. Minutes later, he and his three customers – My son Scott, Scott’s fiancé Michelle Boyd and me – were busy erasing those marks.

In a nearby boat, guide DJ Debevec and his customers – my daughter Jenny and her husband Dennis – were doing the same thing.

Following our guides’ advice, we dropped 3/8th-ounce twister tail jigs tipped with a piece of sucker meat and a salmon egg to the bottom. Then we reeled up a crank and began lifting and dropping the bait so that it kept in contact with the bottom.

Jenny was the first to find success. She felt a tap, set the hook and slowly reeled in a three-pound lake trout from the depths. But before long, everyone got in on the fun.

By the time our half-day trip was done, each of us had caught our limit of four apiece and we had tossed back many more. Most of the fish were in 15 to 24-inch range, not exactly monsters. But they provided steady action, which came as no surprise to Jahn and Debevec. They know that Granby, one of the largest coldwater lakes in Colorado, is loaded with lake trout.

Some of them can reach trophy status. One of Jahn’s customers caught a 25-pound lake trout earlier this year.

But in the heat of summer, most of the fish are smaller –but still fun to fight, especially from the depths.

And especially on the light tackle Jahn uses. He equips his customers with spinning tackle and either 8-pound monofilament line or 15-pound braid with an 8-pound monofilament leader.

That usually makes for an action-packed morning in the prettiest of settings. The mountains surrounding the lake and the glistening, pristine water provide a scenic backdrop for the fishing.

The water is crystal clear and fishermen can look down and see the lake trout arching and twisting as they fight to get loose long before they are brought to the boat.

Jahn instructs his customers to bring the fish up slowly so that they can expel air from their bladders as they are pulled from the depths.

On more than one occasion, we watched as hooked fish left a cloud of bubbles as they were pulled in. Those fish swam off vigorously when they were released.

One thing is certain: Granby has plenty of lake trout. Ewert said the scenic lake probably has the highest density of lake trout in Colorado.

“The bottom is made up of ridges, humps, ledges and depressions, which is textbook for lake trout,” he said. “What lies underwater looks a lot like what we see around the lake above the surface.”

The larger fish could be as old as 30 to 40 years old, Ewert said.  But as the population explodes, Granby is become better known for its densities of lake trout than its true trophies.

“They can easily outstrip their forage,” Ewert said. “That’s why we are trying to encourage  harvest.

“Fish of 18 to 23 inches are very common and provide good eating. By thinning out some of those fish, it should help the growth rate of the overall population.”

Photos by Dennis Schiltz. To reach Beacon Marina, call 970-627-3671.