Like hoisting an oversized stretcher, four strong men heaved the poles out of the giant bathtub sitting in a pickup bed, water poured from the stretcher sides, and huge fins thrashed.

They were carrying a monster, more than 7-feet long. The truck was backed up at the boat launch just below John’s Hole Bridge in Idaho Falls on a recent afternoon.

“This is where we need the weightlifters,” said Dan Anta, assistant manager at the Hagerman fish hatchery.

The men carried the creature down the boat ramp to the water.

“What is it?” asked a small boy, who was watching the proceedings.

“It’s a dinosaur,” teased James Brower, regional communications manager for Idaho Department of Fish and Game. He paused while the men released the behemoth into the water, then he told the truth: “It’s a sturgeon.”

“Can I touch him?” Conor Kennedy, 6, asked.

“Yes, but hurry,” said his father, Patrick Kennedy, a Fish and Game regional fisheries biologist who was standing in shin-deep water, steadying the fish. Mid-torso the fish was as thick as a watermelon. A giddy Conor stepped into the water and petted the fish’s head like it was a puppy.

After a few minutes the sturgeon slowly patrolled the water about the boat dock and then disappeared into the depths of the Snake River. The process was repeated again with a second 7-foot-long sturgeon. This fish circled about in the boat launch area for a minute, then vanished into the dark river water.

The two fish were 25 years old and were removed from the observation pond at Fish and Game’s Hagerman Hatchery northwest of Twin Falls.

“They lived their entire life in their show pond that showcases some big fish,” Kennedy said. “They had fairly high densities and they were looking to reduce their densities in their observation tank.”

On Tuesday, Fish and Game planted eight, 4-foot sturgeon below Gem Lake on the Snake River. At that age, the sturgeon were only a few years old. While 4-foot-long fish may sound big, for sturgeon they’re just youngsters. Kennedy said sturgeon don’t reach adulthood until about age 20 and can live in excess of 100 years old.

Sturgeon are the largest freshwater fish in North America. Before the era of dams on the Snake, Salmon and Columbia rivers, sturgeon grew to 1,500 pounds feasting on abundant runs of salmon, steelhead, lamprey and mussels. Dams now often isolate sturgeon populations and have reduced some of their food sources.

The fish’s long life and slow maturity is one reason why they are catch-and-release only — never removing them from the water — throughout the state. Barbless hooks with a sliding sinker are also required. For tips and rules on Idaho sturgeon fishing, go to idfg.idaho.gov/old-web/docs/fish/sturgeonFishingTips.pdf.

Fish and Game started planting white sturgeon in the Snake River at Idaho Falls in 2007. The river has been stocked the past few springs with about 200 little guys in the 2-foot range. The fish are stocked in five locations — the upper being at the Idaho Falls Dog Park and the lower being below Gem Lake.

Sturgeon tend to be bottom feeders. Brower said some anglers in Idaho Falls are targeting the sturgeon and have been catching them “on a regular basis.”

“Most of them are in the 2- to 3-foot range, they’re not huge, but that’s still a big fish,” Brower said.