Geotechnical work started in June on an abandoned portion of the historic Columbia River highway in Oregon, US.
The Columbia River highway was completed in 1922 and the 113km route used to link Troutdale, a small city near the Sandy River, to The Dalles which is a significant archaeological region but the route was abandoned in the 1950s following construction of the Interstate 84.
The Columbia River Gorge National Scenic Area was established in 1986 and tasked with restoring and reconnecting the fragmented sections and the current work forms the latest phase.
The 6.4km long section located west of Hood River between Wyeth and Starvation Creek is being split into sections starting with a 2km section from Starvation Creek to Lindsey Creek, and followed by a section from Lindsey Creek from Wyeth.
Kristin Stallman coordinator with the Oregon Department of Transportation (ODT) said: “The geotechnical explorations will help us assess the slope stability and provide design data.”
The investigation, which is expected to start in mid-July, includes excavation of 48 test pits and drilling 58 boreholes.
Construction on the first section of the highway is planned to start in spring of 2015.