Despite no warning from the National Weather Service, the skies over the Cascade and Siskiyou mountains opened today and it rained trout into high-mountain lakes.

The Oregon Department of Fish and Wildlife this week conducted aerial fish stocking by infusing hundreds of high-mountain lakes from Mount Hood to Jackson County with 350,000 fingerling trout.

The biennial event using a helicopter included lakes within the Sky Lakes Wilderness Area as well as some remote Siskiyou Mountains lakes, says David Haight, assistant district fish biologist for ODFW in White City.

The helicopter carries a specially made shuttle that actually looks like a space shuttle. It includes 30 individual canisters filled with fingerling trout and water, and the canisters are opened by remote control as the helicopter hovers about 100 feet above a lake.

The canisters contain rainbow, brook and cutthroat trout, all about 3 inches long. ODFW says 95 percent of them survive the free-fall, a much higher percentage than when larger fish were dropped.

The stocking began Monday in the Mount Hood area, and the helicopter-shuttle tandem worked its way south.

In Southern Oregon, lakes in the Blue Lake and Seven Lakes basins of the Sky Lakes Wilderness received fish. In the Siskiyous, Lost, Miller, Tannen, East Tannen and Bolan lakes all received a complement of fish.

Bolan Lake is the only one of those stocked that's accessible by road. The rest can be reached only by trail or by air.

Each lake received anywhere from 500 to 3,500 trout, depending on the water-body's size, Haight says. Eighteen lakes were stocked Thursday in this fashion in two flights, he says.

Most of the trout grow to 8 to 15-plus inches long, providing the backbone of the high-mountain fisheries enjoyed by summer backpackers, horsepackers and hike-in anglers visiting lakes not accessible by roads. Often, anglers literally have these lakes to themselves, casting small spinners or flies for trout not schooled in the ways of anglers.

However, it takes them a few years to grow to the 8-inch minimum size to legally keep and eat.

The aerial stocking has been conducted for decades by ODFW, replacing the more laborious method of carrying bucket-loads of trout in backpacks.

In recent years, helicopter pilots have been joined in the air by agency biologists armed with Global Positioning System units that help increase efficiency and reduce flying time, which costs more than $2,000 an hour.

The lakes in the Sky Lakes Wilderness are all sterile and naturally fishless, Haight says. Though non-native, brook trout are stocked because they are a heartier species than the cutthroat and rainbows stocked elsewhere, he says.

"They do better than the other species in those high, cold, sterile lakes," Haight says.

The high-mountain stocking program is a rarity nationwide, says Mike Gauven, the state's recreational fisheries program manager.

"The thing about Oregon's high lakes is there are not a lot of places in the lower 48 United States where you can have this kind of wilderness fishing experience," Gauven says.

— Reach Mail Tribune reporter Mark Freeman at 541-776-4470 or mfreeman@mailtfribune.com. Follow him on Twitter at www.twitter.com/MTwriterFreeman.