A section of the Historic Columbia River Highway will close for several months. (Courtesy image: ODOT)

A segment of the Historic Columbia River Highway is closing to vehicles, bicyclists and pedestrians for landslide repairs.

The work begins Monday, July 7, just east of Larch Mountain Road, between the Portland Women’s Forum and Vista House. Repairs are focused on an area of ancient landslide that requires a full closure of the highway. The work is estimated to finish by the end of September. At that time the highway will reopen.

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 the Vista House.

During that time detours include:

• Interstate 84 as the route for people traveling through the Columbia River 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, use eastbound I-84 Exit 28
• To reach the Women’s Forum take I-84 Exit 22

History of closures

The section of highway has required regular monitoring and maintenance since it was first built. Over the past decade, the Oregon Department of Transportation has repaved the section as cracks continue to appear and the ground settles.

In March 2025 geotechnical engineers noted the settling had accelerated and caused structural issues for the guardrail and downslope. The safety concerns prompted a temporary closure of the highway section on March 12.

This latest closure/project continues that short-term fix.

The Larch Mountain landslide is a deep, massive complex that occupies more than 100 acres of the Crown Point State Scenic Corridor. The highway skirts the perimeter of the landslide, with about 800 feet crossing an active section.

The original design for the highway called for a viaduct, or land bridge, over the slide area 100 years ago. But that structure was not viable due to the continuous movement/shifting. So it was removed in the 1960s when ODOT built the current alignment.

In 1983 and again in 2007, ODOT constructed a retaining wall to support the Historic Highway. The ground movement sometimes reaches 12 inches in a year. It requires annual repaving/reassessment.