A rock the size of an outhouse smashed one end of a pack bridge deep in the Idaho wilderness, portending potential maintenance headaches throughout the snow-laden Rocky Mountains this spring.
The 348-foot Stoddard suspension bridge across the Salmon River just below the mouth of the Middle Fork was wrecked sometime around March 15. It was the only horse-stock bridge access from Salmon River Canyon to the deeper portions of the Frank Church-River of No Return Wilderness west of Salmon, Idaho.
“I think there’s going to be quite a bit of that, especially over in Idaho,” National Weather Service hydrologist Ray Nickless said Tuesday. “The Salmon area is 130 percent of average precipitation. Here in Missoula, we’re at the second-highest precipitation water-year from October to now. Kalispell is having its first-highest.”
Precipitation differs from snowpack, which is running around average in most areas along the Montana-Idaho border. Last October got the record started with heavy rains before the weather turned cold enough to snow. And this February and March have seen a lot of rain-on-snow events that soak the landscape without moving the snow depth.
The resulting waterlogged ground has produced landslides, mudslides, streambank erosion and damage to roads and railroad lines. Nickless said numerous roads in the Clearwater Basin west of Lolo Pass have been damaged, and Montana Rail Link’s main line through northern Idaho washed out last Friday, derailing 52 empty coal cars along Lake Pend Oreille.
The Clark Fork River at Bonner was running 2,230 cubic feet per second, well above the median 976 cfs for March 21. The Bitterroot was even livelier, pushing 5,980 cfs compared to its median 1,210 cfs for this date (see related story). And up Flathead County, the Middle Fork of the Flathead River was 10 times normal flow at 6,630 cfs and the North Fork of the Flathead was five times bigger than usual at 4,780 cfs.
The Lochsa and Selway river basin snowpack stands at 113 percent of average, giving hope to rafters and kayakers in search of long-season whitewater. However, a runoff surge over the weekend wiped out the popular Jerry Johnson hot springs soaking pool when the Lochsa jumped from 4,500 cfs to more than 20,000 cfs. Salmon-Challis National Forest spokeswoman Amy Baumer said the Salmon River was running strong at the Stoddard bridge location and the backcountry road there occasionally was limited to one lane of travel because of rock and snow slides.
In the Bitterroot National Forest, spokesman Tod McKay said the usual May 15 opening date for the Magruder Corridor Road probably was going to get pushed back because of at least 60 snow slides along its 100-mile length.
“Even though the calendar says it's spring it's certainly still winter back in the forest,” McKay said. “It all depends on the next couple of months. If we get some warm, moist windy weather on that above-average snowpack the avalanches, rock slides and tree falls will obviously rise.”