PORTLAND, Ore. – The massive collapse of glacial debris last winter wiped out a crucial stretch of the Timberline Trail around Mount Hood, and U.S. Forest Service officials don’t know whether or how they will repair it.
The damage, which emerged when snow melted, severs one of the most popular hiking circuits in the Cascades. Hikers trying to complete the 41-mile loop will find a steep drop-off hundreds of feet high where the trail used to traverse below Eliot Glacier on Mount Hood’s north side.
The remaining slope is so unstable and dangerous, there’s no way to rebuild the trail, said Kevin Slagle, who manages recreation in that section of the Mount Hood National Forest. “It’s a cliff made out of sand, with rocks in it the size of Volkswagens. You don’t want to be near it.”
Thousands of hikers trek the Timberline Trail each year, many circling the mountain over three or four days. Forest Service spokesman Rick Acosta said he couldn’t find anyone who recalled such serious damage cutting off the trail before.
The section of trail apparently collapsed during a massive rainstorm in November. Water may have pooled inside the Eliot Glacier and then burst out, undermining slopes below the glacier and causing them to slide, said Tom DeRoo, a Forest Service geologist.
The slopes, called moraines, are formed of rocks, gravel and sand deposited by the glacier over centuries. When the glacier was larger, its ice held the slopes in place, but a warming climate has melted its lower reaches. The collapsing slopes beneath the glacier mixed with the rush of water, forming a rocky torrent called a debris flow. The debris flow picked up more rocks and trees as it continued down the mountain, into the Hood River and all the way to the Columbia River, where it formed a new delta and sandbar.
“We’re going to see a lot more of this as the glaciers recede,” said Scott Burns, a Portland State University geology professor.
The Forest Service might consider rebuilding the Timberline Trail lower on the mountain, below the collapse, Slagle said. But that area is steep. Building a trail there would be expensive and could require a suspension or other bridge, he said.
A complication is that the section of trail lies inside a wilderness area, which is supposed to remain undeveloped. Mechanized equipment that might be necessary to install structures such as a suspension bridge with steel cables generally is not permitted.
Even rebuilding the trail, if it involves carving out a significant new path, probably would violate wilderness protections, said TinaMarie Ekker, policy director at Wilderness Watch, a wilderness advocacy group in Missoula, Mont.
“There’s nothing that says they can go in and reconstruct a trail taken out by nature,” she said.
The other problem is that another collapse could destroy a new section of trail anyway.
“I’m sure people want the Timberline Trail back,” Slagle said, “but we don’t want to waste a lot of taxpayers’ money on something that’s going to wash away in a year.”