JACKSON -- High in the Wind River Mountain Range, just north of Wyoming's highest peak, is a natural trench that runs like a hallway straight through a glacier to where a lake used to be.

On Sept. 6, Mother Nature uncorked the lake, releasing 600 million gallons of water through the trough, surging down into Dinwoody Creek.

It wouldn't be until Oct. 19 that anybody would see up close the glacier that caused the flood. It wouldn't be until two men hiked more than 80 miles in a loop around the northern Wind River Range to document the ice wall, sediment trench, and tons of granitic rubble.

Hank Williams, 30, and Aaron Deschu, 27, were the first -- as far as they know -- to hike to the Grasshopper Glacier in the Winds, and see the origin of the flood -- an unnamed lake at about 12,000 feet. The deluge flooded outfitter camps and shot U.S. Forest Service hydrology gauges up from a measure of 200 cubic feet per second to 900 cubic feet.

"It wasn't easy to get to," Williams said, "we had to go through a tremendous amount of terrain. The closest trailhead is about 20 miles back."

The pair planned their trip in the summer and rerouted it after the glacier dam break was confirmed in flyovers Sept. 22.

"When we crested the hill, we could see the ice dam that was on the northern shore, about three-quarters of a mile away," Williams, a U.S. Forest Service employee, said. "It looked like a huge vertical ice wall. The most impressive feature was a trench on the northern point of where the lake used to be, and there was still lots of mud and water flowing into it."

The basic geology of the event is this: The lake was contained by a glacier -- a slowly moving mass of ice. At some point, that lake was set free.

Although the exact cause of this Sept. 6 event is still being studied, scientists think the glacier began melting in pockets beneath the surface, causing water to carve through the ice and pour out over a trench of rock on the northern end of the glacier.

As this melting increased, enough pressure from the water built up to crack the wall of ice that remained between the lake and the trench, releasing millions of gallons of water down about eight miles to Dinwoody Creek.

Williams said the duo walked to where the lake used to be -- an area now frozen over -- and into the trench that went "completely through" the glacier.

"There was a lot of sediment in the trench," Williams said. "There was a band of sediment on either side and some sediment on the bottom. It was like being in a gigantic hallway. ... It was pretty loud in there. All you could hear was water and condensation."

The Grasshopper Glacier lies on the east side of the Continental Divide, about two miles north of Gannett Peak.

Liz Oswald is a hydrologist with the U.S. Forest Service, and was the first to fly over the area to map the flood on Sept. 22.

"Is something like this caused by global warming? That's the first thing people ask me," she said. "Who knows? If it is, you've got to sort of wonder, what are humans' anthropogenic influences on climate? The scientific community is really divided on that question."

Oswald said it could be global warming that caused the glacier to begin melting, or it could be a climatic cycle the world is in now.

"That's part of the interest, how exactly did it happen?" she said.

The interest in the Grasshopper Glacier's outburst has spanned the country. Associated Press stories were picked up in newspapers throughout the Rocky Mountains and in San Francisco.

"From my point of view, it's unique because it's an event that happened here and not in Alaska or Iceland," Oswald said. "It also happened in a place where it didn't destroy any homes or cause loss of life. That sometimes happens. ... If this were above Estes Park or something, that would have been a different deal," she said, referring to the Rocky Mountain National Park gateway community in Colorado.

Floods of this nature are not unusual in areas of glacial activity. In fact, the area around Missoula, Mont., was formed after glaciers broke through, lakes were released and massive floods carved through the area.

"These events, they occur for different reasons," Oswald said. "Sometimes they are triggered by volcanism -- heat warms up the ice and it melts and a lake formed that's impounded and then it gives way and floods. Earthquakes, seismic activity or a storm event -- like a thunderstorm that hits locally."

But high in the Winds, Oswald said, there was no record of seismic activity and there isn't any volcanic activity in that area. Scientists hope to look at the sediment deposits left by the flood for clues.

The occurrence on Sept. 6, although not uncommon, has given scientists reason to look elsewhere in the Winds for possible repeat floods.

"From what I can see, there isn't another glacier that has this sort of configuration," Oswald said. "There are lakes that are appearing where they haven't been before. It's not something that you can directly tie to a cause and effect."