Historic cabin burns in Clearwater

Colt Killed Cabin, located southeast of Powell Ranger Station near trails into the Selway-Bitterroot Wilderness, burned to the ground in June.

Clearwater National Forest officials are seeking information about the fire and would like to hear from anyone who visited the cabin this spring before it burned.

The historic cabin, built in the early 1930s, initially served as a remote Forest Service way station.

In recent years the cabin has been visited regularly by wilderness visitors and Colt Killed Creek kayakers.

The cabin was slated to become a Forest Service rental for people seeking a rustic experience deep in the forest.

Contact: Jennifer Armetta, Powell Ranger Station (208) 942-0007.

GEOLOGY

Sierras older than we thought

Prehistoric raindrops locked in crumbling boulders have led Stanford University researchers to conclude the Sierra Nevada is at least 40 million years old, much older than previously thought.

New geological evidence shows that the traditional estimate of 3 million to 5 million years old appears far too low.

There is no debate about the age of the rocks beneath the Sierra: radioactive dating shows they are up to 120 million years old. But scientists have not been able to agree on when the rocks lurched upward to create the mountain range.

Subtle variations in hydrogen isotopes in the rainwater samples found in dry river tributaries helped the scientists estimate cloud temperatures at the time the raindrops fell millions of years ago, which in turn allowed them to estimate the height of the clouds, and thus the height of the range.

The findings are “at odds with more traditional geologic evidence” about primeval mountain-building, and could upend traditional explanations if they are verified, said Craig Jones of the University of Colorado.

NATIONAL PARKS

Wrangell-St. Elias ATV ban sought

Conservation organizations are suing to ban recreational four-wheelers from Wrangell-St. Elias National Park and Preserve in Alaska, saying the National Park Service didn’t follow its own rules in allowing the vehicles in the 1980s.

The all-terrain vehicles harm vegetation that protects permafrost, leaving scars that make traveling difficult for other users, plaintiffs said.

The Washington, D.C.-based National Parks Conservation Association is the lead plaintiff in the federal lawsuit filed this month.

Wrangell-St. Elias – the country’s largest national park at more than 13 million acres – is the only national park in Alaska that allows recreational ATV use, said Park Service spokesman John Quinley.

About 200 recreational ATV permits are issued a year, mostly to sport hunters in the fall, Quinley said. Sport hunting is allowed in the preserve but not the park.

Park officials never did an environmental impact review or a finding to show that ATV use is compatible with park purposes, such as scenic beauty, healthy wildlife and backpacking, said Jim Stratton, Alaska director for National Parks Conservation Association.

Rod Arno, executive director of the pro-hunting Alaska Outdoor Council, said damage on the trails is insignificant compared with the size of the park’s habitat.

ENVIRONMENT

Mercury increase in bald eagles

Heightened levels of mercury have killed two bald eagles in Montana, and been detected in about 10 others, and officials aren’t sure why.

The Montana Raptor Conservation Center in Bozeman has been testing eagles for the element since a bird brought in several months ago with signs of lead poisoning tested negative for lead but positive for mercury.

Since then, the center has detected heightened levels of mercury in 10 to 12 bald eagles, and two have died.

It’s too early to tell if the high levels are simply a result of investigators looking for it or if something else is going on.

Overall bald eagle population is doing well, but those found with mercury “raise some red flags,” one researcher said.

Montana has nearly 400 breeding pairs of bald eagles compared with just 12 in 1978. A 1972 ban of the pesticide DDT, which caused eagles’ eggs to thin and break, and increased protection measures are credited with increasing the population of bald eagles nationwide.

The U.S. Fish and Wildlife Service is proposing to remove the animal from the endangered species list.