WYDOT Completes WY-HW 22 Detour, Reopens Teton Pass to Commuter & Tourist Traffic

WYDOT Completes WY-HW 22 Detour, Reopens Teton Pass to Commuter & Tourist Traffic

All Images: Courtesy of Wyoming Department of Transportation

The Wyoming Department of Transportation (WYDOT) has announced the reopening of Wyoming State Highway 22, better known as Teton Pass. With the completion of a paved two-lane detour at milepost 12.8, as well as the successful recovery from mudslides at milepost 15, the pass is now operational and open for tourist and commuter traffic between Victor, Idaho and Jackson, Wyoming.

Following the collapse of a major section of road at milepost 12.8 in early June, 2024, WYDOT and Evans Construction quickly got to work constructing a detour on the pass. They initially directed traffic between Idaho and Wyoming to head South and drive through Snake River Canyon. While this was the only course of action at the time, it was more than an inconvenience for travelers as it extended what is usually a 30 – 40 minute drive by nearly two hours.

Between five and eight thousand workers commute over the pass every day, with the majority of them traveling from Idaho to Jackson, Wyoming for work. The pass closure put immense economic stress on the residents and businesses in the area, and to have it back open within such a short time is a huge relief to locals.

An aerial view of the finished detour at milepost 12.8 on Teton Pass

This achievement is not to be understated. Since the road gave way on June 8th, “Evans Construction and its subcontractors [have] worked around the clock, even through Father’s Day weekend, to build the temporary detour,” read the press release published by WYDOT on June 28th. The new detour consists of two paved lanes, each 12 feet wide, and will direct traffic along the same route they are used to heading over Teton Pass.

“While temporary, this detour safely reconnects communities and gives commuting families their valuable personal time back. This process underscores the vital importance of infrastructure like mountain passes that connect people to work, family, medical care, affordable housing and other necessities. I think every Wyoming resident or regional commuter can be proud of their transportation department. WYDOT staff from a variety of departments and areas of expertise rolled up their sleeves and got to work for the people – a master level class in public service.” – WYDOT Director Darin Westby

The original collapse, which occured on June 8th at milepost 12.8

Now, WYDOT and its engineering affiliates are looking to ensure that safety procedures are followed and conditions are monitored, ensuring that accidents in the future can be better predicted and mitigated. This is a difficult task, but far from impossible. The accident gave engineers many takeaways and factors to look for in the future.

For example, the slide at milepost 12.8 was not a random act of unforeseeable nature. This section of road, known as “Big Fill”, was a man-made mound constructed in the 1960s that reduced the slope grade to 10%. While effective, it has been vulnerable to water over the last two decades and was built on top of a natural layer of clay, according to WYDOT. Over six decades of pressure, recent groundwater, and the failure of this lower layer of clay culminated in the 200-foot collapse we saw in early June.

There were signs such as cracks in the road leading up to the collapse, which WYDOT says will be more carefully noted in the future. The immense saturation and potentially weak ground layers are both items that engineers have identified and will be looking for in other areas around Teton Pass.

Crews work to pave the road at WY-HW 22 milepost 12.8 on June 25th

The new section of the constructed detour is said to be far more stable. There is much less water moving through the ground thanks to a dwindling run-off season, and the soil is dry. It hasn’t experienced the loading and compression that the soils under the Big Fill slide had endured for the last six decades. For context, the image below shows the new detour, positioned north of the previous section. The detour is 600 feet long, with an 11.2% grade and a sharper curve, according to WYDOT.

While they’ve expressed confidence in their work, WYDOT will be prioritizing safety as the detour is opened to the public. They will be searching for potentially dangerous geological activity, doing so by using, “real-time information on subsurface movement and ground-based radar detection, along with personnel inspections.” WYDOT has not confirmed whether or not they will establish a 24/7 personal presence on the pass through the summer.

The temporary detour received a factor of safety score of 1.2 which reflects the stability of the structure. A factor of safety of 1 means the structure can support exactly its expected load, with 1.5 meaning that it can support one and a half times the expected load. 1.1 is the minimum factor of safety acceptable to WYDOT’s professional licensed engineers.

The finished detour in all its glory, constructed to the viewer’s left of the Big Fill collapse

The incredible work conducted by WYDOT and Evans Construction crew is commendable in every way. There are still steps to be taken to ensure safety for all future travelers, but to have a completed detour just three weeks after the initial collapse is a win for tourists, local employees, business and the communities that make up both sides of the Teton Valley. Of course, there is more work to be done. Officials have stated that they hope to have a permanent rebuilt section of Teton Pass completed by November of 2024, before the worst of winter sets in. They have not yet announced a timeline for the final rebuild.

This is a developing story. FREESKIER will continue to update readers as events change.

Click here for the official WYDOT Press Release regarding the reopening of Wyoming State Highway 22

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