After driving five dust-choked miles by all-terrain vehicle, hiking three miles while crossing Lower Deer Creek 21 times and losing and then gaining almost 2,000 feet elevation, Jeremiah Wood was elated to see two inch-long cutthroat trout fry dart across a boulder-formed pool.

"Woo-hoo!" he yelled, raising his arms in triumph like a new father in the maternity ward.

Minutes later the Fish, Wildlife and Parks fisheries biologist and technician Ben Bailey had found more of the fry finning in shallow side channels.

"I counted 15 in 50 feet of stream," Wood said, with a wide smile. "I'm going to call this a success. There could have been none."

Squeezed out

Lower Deer Creek's native Yellowstone cutthroat trout have suffered some tough times lately.

In 2006, the Derby fire swept through much of their habitat, leaving many of the steep hillsides southeast of Big Timber in the foothills of the Beartooth Mountains barren of green trees. Fearful that runoff would choke the stream with debris after the fire, that fall Montana Fish, Wildlife and Parks moved some of the cutthroat to a stream near Luther to ensure that a few were protected.

But even before that, the fish had faced competition from non-native rainbow and brown trout. Brown trout feed on the cutthroat fry, and rainbows will interbreed.

"The cutthroat are getting squeezed," Wood said. "In Lower Deer Creek, we're starting to see more hybridization with rainbows, and they're moving up the drainage. We're seeing more and more brown trout, probably because of the drought."

One previous attempt to remedy the situation involved introducing hatchery-raised Yellowstone cutthroat farther upstream, above a 30-foot waterfall that would provide a natural barrier to non-native fish. But there was no evidence the hatchery trout ever reproduced.

Another attempt to protect the fish involved removing cutthroats from Lower Deer Creek and releasing them above the barrier falls, but those fish seemed to have all returned downstream.

The Lower Deer Creek fish have also suffered through low stream flows from drought. Low flows, in addition to restricting habitat, can also mean warmer water. Irrigation use of the stream typically dewaters the lower portion of the creek every summer, cutting it off from the Yellowstone River.

New technique

This spring, taking a new tack, FWP decided to take eggs from spawning Lower Deer Creek cutthroats, fertilize them and rush them upstream to establish a new population.

To hold the eggs in the gravel, Wood and others built small cups made from perforated polypropylene pipe. Inside the 4-inch pipes, which are capped on one end, the fisheries biologist and technicians laid a layer of gravel, then eggs, then gravel and eggs until the cup was filled. Then the cups were buried in the gravel of Lower Deer Creek, a stake holding them in place with an attached wire.

"They allow you to place the eggs in the gravel easily and provide some protection from predators," Wood said.

The egg incubation is a technique that has proven successful in the Elkhorn Mountains, south of Helena.

In all, about 3,000 eggs were gathered and fertilized. They were hauled into their incubation site by backpack on a hot June day. The crew had to stop at stream crossings to add cool water to keep the eggs viable.

"There's only a short period of time to move them before they get sensitive," said Ken Frazer, fisheries manager for south-central Montana.

The creek was high in June but had dropped substantially when Wood returned in July to check on the egg incubators. He moved them deeper to ensure they'd be underwater when the fish finally emerged.

The stream had dropped substantially by last Thursday, when Wood again made the trek to check on the fish, but apparently all the hard work had paid off. He counted a total of about 30 fry in a short section of the stream.

Important to protect

Frazer said projects like the one on Lower Deer Creek are important to preserving local fishes' adaptations to specific waters.

"We're always looking to see whether there are local adaptations," Frazer said. "Our goal is to preserve these species as best we can."

The agency also is trying to prevent an endangered-species listing of the fish, which would bring with it a host of federal restrictions. Yellowstone cutthroats have seen a substantial decline in their population base, especially in Yellowstone Lake, from disease and competition from non-natives. A 2007 FWP assessment showed the fish occupied only 43 percent of the streams they historically lived in, but now occupied more than 200 lakes where they weren't previously found.

So the upstream planting of Yellowstone cutthroats could be compared to a biological safety deposit box.

"If the population gets compromised downstream, we'll have something to re-establish it," Wood said.

A similar experiment was made this spring at Duck Creek in the Crazy Mountains. Survival of fish there was about 20 percent, Wood said, possibly because the water is silty.

"It's low, but probably pretty close to the natural survival," Wood said. "If 15 to 20 fish make it to adulthood, that's typical."

One down

Since this is the first year in a three-year project, Wood hopes for more success. Many of the kinks have been worked out of the system - they now know where and when to find spawning cutthroats that can be captured and milked, they know the egg incubators work but must be placed deep into the stream to allow the water to drop after runoff.

One thing that won't change is the difficult terrain and distance the crew has to deal with to reach the adult fish, and then to backpack the eggs in. It's like climbing to the top of a 200-story building situated at an elevation of more than 5,300 feet while carrying about 42 pounds of sloshing, liquid weight - all to ensure the birth of a few fish. It's a burden maybe only an expectant mother - or in Wood's case, an expectant father - can relate to.

Contact Brett French at french@billingsgazette.com or at 657-1387.