HIGHER ED WITH A VIEW

‘Students’ from all over hear Beartooth lectures

Presentations highlight geologic, glacial history of mountains
2009-07-15T22:05:00Z ‘Students’ from all over hear Beartooth lecturesBRETT FRENCH Of The Gazette Staff The Billings Gazette
July 15, 2009 10:05 pm  • 

VISTA POINT - At 9,500 feet above sea level, Drew Downs may have the loftiest lecture platform in Montana.

Every Friday and Saturday at 2 p.m., as part of his summer work for the Beartooth Ranger District, Downs, 24, gives a talk on the geologic and glacial history of the Beartooth Mountains. His lectern is at the end of an arête - a protrusion of rock left between the deeply carved Rock Creek and Wyoming Creek drainages. Appropriately, the walls surrounding the viewing area are made of native rock.

The audience for the talks at the turnout on U.S. Highway 212 can range from a busload of 40 schoolchildren from nearby Red Lodge to as few as a half-dozen motorists. The "students" taking in the talks so far have represented every U.S. state and several foreign countries, Downs said.

No matter the number or where they come from, all of the tourists get a 15-minute crash course on why the Beartooth Mountains are unique, complete with rock visual aids fist-sized and larger - diorite, dolomite and Flathead sandstone.

The Beartooths are composed of some of the oldest rocks on the planet. While Earth is estimated to be about 4.5 billion years old, igneous rocks in the Beartooths, mostly granite, are about 3.9 billion years old.

"Ninety-nine percent of the rock out here is granite," Downs said.

Outcrops of sedimentary rocks like limestone, sandstones and shales are found around the perimeter of the Beartooths, often at the entrances to the mountain canyons. Examples are the Palisades north of Red Lodge and the Meeteetse Spires south of town.

The Beartooths rose from the surrounding landscape as the North American plate, upon which Montana sits, was thrust upward by the Pacific plate sliding underneath. The two plates are still colliding, producing faults and earthquakes. The theory is that before being eroded to their present height - Granite Peak in the Beartooths is the highest mountain in Montana at 12,807 feet elevation - the Beartooths were 3,000 to 8,000 feet higher.

"Eventually, they'll be as flat as Kansas," Downs said, thanks to erosion.

The Beartooths also were shaped into their present state by the grinding action of retreating glaciers over the past 2 million years. A prime example was right behind Downs, the U-shaped Rock Creek drainage. Near Cooke City, glaciers carving around the base of the mountains left behind what geologist call horns, in this case the peaks Index and Pilot. One of the oddest finds in the Beartooths is that the glaciers retreated without scouring away sedimentary rock that make up Beartooth and Clay buttes, just over the top of the pass. Downs said no one knows for sure how the rocks avoided being washed out, but one theory is that they sit in the middle of a depression that was somewhat shielded and that because of the elevation, they were some of the last places to thaw.

GeoCorps

Downs, who has a master's degree in geology from Southern Illinois University, got linked to the Beartooth post through the Geological Society of America. He may have had an edge over the 30 other applicants for the job because he had done field work in the Beartooths through the Yellowstone-Bighorn Research Association, which has a station for geologists outside Red Lodge.

Downs' position is part of the GeoCorps America Program, created and funded by the Geological Society of America to increase information about geosciences. The program started in 1997 with just two positions. As of last year, GeoCorps had placed 66 people in seasonal positions at national parks, forests and Bureau of Land Management sites.

Last year, the program near the top of Beartooth Pass attracted about 300 visitors.

"The GeoCorps thing has been a great deal for us," said Dan Seifert, program manager for the Beartooth Ranger District. "There's just such incredible geology here. A lot of the universities do field camps out of YRBA."

During the rest of the week, Downs helps the Beartooth Ranger District by mapping old mine adits (a type of horizontal entrance) and assessing their damage. He also is mapping different rock types along the Beartooth Front and possibly some cave locations in the Pryor Mountains.

It's a position he's relishing for the summer. He called the Beartooths a phenomenal region for geologists because of the rock's exposure.

"It's hard to find rocks this exposed and so well studied," he said.

He noted that the Stillwater area, the only site in North America where platinum and palladium are mined, offer a geological trip through the history of Earth.

"This is stuff you'd normally only see way down low," he said. "But here it's all tilted up and been exposed at the surface. You can see all these different layers. There are 4 billion years here within a mile's walk through geological history. There're not many places you can do that."

An avid hiker and backpacker, Downs is using his off hours to explore the rugged mountains.

"I tend to have a problem not looking up," he said. "It starts to be a real problem when I pay more attention to the rocks and trip."

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

Program examines geology of Breaks
A free program about the geology of the Missouri River Breaks is offered Monday at 7 p.m. at the Missouri Breaks Interpretive Center in Fort Benton.
The program is open to the public and will last about one hour.
The presentation will be given by Robin Canavan, a GeoCorps intern who is working at the interpretive center this summer.

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