BIGHORN NATIONAL FOREST, Wyo. — The scene could have been in a period film — a handful of men wrapping rope around a mule to secure metal tanks to the saddle.
The mule was neighing. Water nearby was rushing. There was no motorized traffic for miles.
The mule then marched up a steep canyon, transporting the precious cargo.
Inside the 10-gallon metal tanks were water, ice and Yellowstone cutthroat trout.
"We're doing our darnedest in places like this to give them real estate and isolate them," said Mark Smith, a fisheries biologist with the Wyoming Game and Fish Department. "That's key. They need to be in an area without any (invasive species of) trout. They tend to lose."
The Yellowstone cutthroat trout is a native species. The brook trout, the rainbow trout and "mutt" trout that are a product of the cutthroats breeding with the rainbows have crowded out cutthroats in northern Wyoming rivers and creeks over the past 100 years.
Smith has been at the helm of the six-year project to eliminate invasive species and restore the Yellowstone cutthroat to its historical reign of the waterways.
While Yellowstone cutthroat trout were the stars of their recent relocation in South Paintrock Creek in the Big Horn Mountains, the horses and mules that hauled them stole the show.
Humans — from volunteers to employees of Wyoming Game and Fish and the U.S. Forest Service — played the supporting cast in the trout relocation, from hiking down and up the canyon, to trudging through water, to handling electrical charging equipment that draws the trout to nets.
St. Paul, Minn., resident Megan Ryan was one of the volunteers.
"I drove out here with my husband and 4-year-old and 7-year-old in a 1982 Westfalia VW bus," she said. "I needed a break from them."
She was visiting her brother in Thermopolis, and he talked her into helping him take his mules to the Big Horns, sleeping in his horse trailer along the way.
Her brother, Kevin Ryan, has helped Wyoming Game and Fish with past projects.
"For the mules, they need work, they need a job," he said.
The mules and horses — six total — were necessary because of the terrain.
The area from which the fish were plucked was remote — off U.S. Highway 16, across a 10-mile dirt Forest Service road, over a rocky two-track road, and down a trail on foot into the canyon.
The canyon trail was too steep for all-terrain vehicles that are often employed in fish relocation. The canyon was too narrow to land a helicopter, also sometimes employed in relocation efforts.
Hence the hoof help.
While horses and mules are helping restore the Yellowstone cutthroat, they likely were part of operations that threatened their demise.
In the early 1900s, brook trout and other nonnative fish were introduced to the Big Horns. Back then, the goal was species diversity.
"It was really Johnny Appleseed as to where you put the fish — wherever you thought they would do well," Smith said.
Not much was known in those days about how nonnative species affect ecosystems.
"It was the Game and Fish Department as well as local sporting clubs," Smith said. "They would put them on railroad cars in the East and transport them."
From the trains, the fish may have gotten to remote regions by horse.
Over time, the "alien invaders," as Smith called them, took over.
In the case of the brook trout, they spawn in the fall, and hatch earlier in the year. Their babies are large by the time Yellowstone cutthroat are born, and better able to defend an area.
A two-mile area of South Paintrock Creek was an exception, largely untainted by invasive fish. Almost 150 cutthroats were collected and hauled to their new home, along another portion of South Paintrock Creek that had been previously cleared of invasive species.
To get to their new home, the trout traveled in time to the conveniences of modern technology: They were removed from the horses and mules and chauffeured in a pickup that was equipped with a tank of water and oxygen.
The horses' and mules' work was done, and they returned to their pastures and stables in Thermopolis, Cody and Worland.
Swimming away in their new section of stream, the cutthroats will be monitored by Game and Fish staff. In the water, they will meet another population of relocated cutthroats.
"Next year, we'll find a bunch of these (relocated trout) and oodles and oodles of two-inch babies that are their offspring," Smith said.
Information from: Casper (Wyo.) Star-Tribune, http://www.trib.com