HUNTSVILLE, Weber County — It was payback time . . . 20 moose for 35 Rocky Mountain bighorn sheep and a couple dozen birds that go by the unpronounceable name of ptarmigan.

Colorado gave Utah the sheep and the birds. Now, Utah is sending 20 moose, cows and calves, to Colorado.

"It's part of a very successful program," said Justin Dolling, wildlife manager for the Utah Division of Wildlife Resources, as he listened intently for the chop-chop of the rotors of a helicopter flying in the first moose.

Utah has been trying to increase its bighorn-sheep range and needed Colorado's help. Now, Colorado is trying to establish a moose herd on Grand Mesa, about 30 miles east of Grand Junction.

"Records from our first superintendent in what was then called Battlement Reserve indicated that there were moose in the area. The challenge with moose is they're incredibly large and easy to hunt because they do not have the typical fear of man. A lot of experts think they were hunted out of the area by early settlers and early Americans because they are a great meat source and they are easy to hunt," explained Randy Hampton, pubic information officer with the Colorado Division of Wildlife.

"At times we've seen a single moose on Grand Mesa, maybe every couple of years. But we wouldn't find other moose so there was no way to establish a population even though it's great habitat. We needed Utah's help."

Even though it was a federal holiday Monday, about 40 wildlife offices showed up to help in the capture effort in the foothills east of Huntsville. The capture area, said Dolling, "holds more moose than what our management plan calls for. This is a very productive area. Our management plan calls for 650 moose. We have more than 1,000 on the unit.

"The 20 moose we take are not going to impact the unit at all."

While capture pens can be used to corral antelope, and drop nets can be used to trap bighorn sheep lured under them by food, moose — being a solitary animal — are more difficult to catch. They can either be tranquilized or tangled up in a net shot from a gun.

"We chose to use the net gun rather than tranquilize the animals because it's far less stressful," said Dolling. "We are also going to maintain cow/calf relationships. If we capture a cow with a calf we'll keep them together and release them together."

A capture crew flies over a moose and fires a 12-by-12-foot net from a pressure gun. The moose becomes tangled in the net and falls to the ground. The crew, called muggers, then jumps from the helicopter, hobbles the moose and places it in a sling with carrying handles.