Stability of rockslide being studied

Workers said they would need to break the rocks that slid into smaller rocks before they will be able to move them.August Frank Lewiston Tribune

LEWISTON — Idaho remains a state divided today and transportation officials don’t know when they may be able to safely clear a rockslide near Riggins to restore north-south traffic on U.S. Highway 95.

The road has been blocked since Friday morning, when rocks the size of vehicles spilled across it. Officials at the Idaho Transportation Department had hoped to be able to restore traffic by Sunday. They were working on a temporary road around the slide 6 miles south of Riggins, but had to pull back late Saturday afternoon when a large crack appeared in the rocks above the landslide site.

Outside experts are expected to visit the site today and determine what needs to be done to make the area safe for workers and eventually for traffic, said Megan Sausser, a spokeswoman for the department. The highway is likely to remain closed for much of today and perhaps longer.

“The very nature of slides is unpredictable,” said Jared Hopkins, operations engineer for the department. “At this time, we’re not sure when we will be able to open the highway, but we are continuing to conduct geotechnical surveys and (today) will have experts on the slope to pry off any loose material and further analyze its condition.”

In the meantime travelers have few options aside from an hours long detour through eastern Oregon and southeastern Washington. The Idaho County Sheriff’s office posted on its Facebook Page that the nearby Pollock Road cannot be used as a detour. The rural road once would have worked as an alternative route but damage to it several years essentially cut the road in two. The sheriff’s office said the road is posted as closed and those who disobey the closure will be ticketed.

The U.S. Forest Service also warned travelers against using the remote Sheep Creek Road to bypass the slide. The narrow, dirt and gravel backcountry route east of Riggins climbs out of the Salmon River Canyon via a series of tight switchbacks and then crosses mountainous terrain to reach McCall. The road is not suitable for sedans or vehicles pulling trailers and is not advised for people unfamiliar with driving rough mountain roads, according to the agency.

Idaho is unusual in that there is only one highway — U.S. Highway 95 — connecting its northern and southern halves. Between New Meadows and Riggins, the highway largely follows the Little Salmon River as it squeezes between the Seven Devils Range and Hells Canyon to the west and mountains of central Idaho to the east. Farther east sits the massive Frank Church River of No Return Wilderness Area.

Motorists looking to travel between the northern and southern halves of the state have little choice but to use the highway when it is open or take routes through eastern Oregon and Washington to the west or Montana to the east. There is a history of short term closures of the highway because of slides, especially between Grangeville and New Meadows. The area of the recent blockage was also the site of a 2012 rockslide that disrupted traffic for a time. A steep hillside in the Salmon River canyon about 30 miles south of Grangeville and near the Steelhead Inn has slid numerous times, including in 1997. That year massive flooding also closed the highway south of Riggins.

Barker may be contacted at ebarker@lmtribune.com or at (208) 848-2273. Follow him on Twitter @ezebarker.

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