TROUTDALE – The Historic Columbia River Highway, also known as U.S. 30, will close to vehicles, bicyclists and pedestrians for landslide repairs just east of Larch Mountain Road, between Portland Women’s Forum and Vista House, starting Monday, July 7.
Repairs to an area of ancient landslide will require full closure of the historic highway at Larch Mountain Road. We estimate that the work will be completed and that this section of the historic highway will reopen by the end of September.
The closure around the work zone will be from milepost 8.7, where the Historic Highway and Larch Mountain Road split, to milepost 9.5 at Vista House.
Detours
- Interstate 84 is the detour route for people traveling through the gorge.
- Exit 22 at Corbett Hill Road and Exit 28 at Bridal Veil will remain open to access destinations along the Historic Highway.
- To reach Vista House, travelers should use eastbound I-84 Exit 28 to Bridal Veil and travel west on the historic highway.
- Visitors to Portland Women’s Forum should take I-84 Exit 22 to Corbett Hill Road to access the forum.
Please visit Tripcheck.com for the latest information on road conditions.
NOTE: this fall, the East Viaduct on the historic highway at Multnomah Falls will close to all traffic to continue a repair project through spring 2026. During the viaduct closure, vehicles traveling westbound from Hood River will be turned around at the Oneonta Trailhead before reaching the Multnomah Falls Lodge.
Background
The section of the historic highway just west of Vista House travels through an ancient slide area, which has required regular monitoring and maintenance ever since the highway was first built. Over the past decade, ODOT has repaved this section as cracks have appeared and the ground has settled.
In March 2025, geotechnical engineers noted that settling had accelerated and caused additional structural issues for guardrail and downslope. These safety concerns prompted closure of this section of the highway on March 12.
After temporary repairs and dry weather, we reopened this section of the highway March 25 while we designed a longer-term repair to be completed this summer.
History
The Larch Mountain landslide is a deep, massive landslide complex that occupies more than 100 acres of the Crown Point State Scenic Corridor. The historic highway skirts around the perimeter of this massive landslide, and about 800 feet of the highway crosses an active section of the landslide just east of the intersection with Larch Mountain Road, about half a mile west of Crown Point.
When the Historic Highway was built over 100 years ago, the ancient Larch Mountain Slide was a challenge. The original design for the highway at this location was a viaduct, or a bridge over land, though the structure could not accommodate the continuous movement of the landslide. This viaduct was removed in the 1960s when ODOT built the current alignment.
In 1983, and then again in 2007, ODOT constructed a retaining wall to support the historic highway. Continued ground movement, sometimes up to 12 inches in a year has required annual repaving and reassessment.