Residents of Jackson, Wyoming are no strangers to the dangers of avalanches. Milepost 151 on US 89/191, otherwise designated by Wyoming Department of Transportation (WYDOT) as ‘151 Avalanche,’ historically experiences one to two avalanches each year. Luckily, no deaths have been associated with the avalanches; however, the avalanches have struck vehicles, caused accidents, and created plenty of havoc for winter driving.
The ‘Jackson South Snow Structures’ Project was Born
In general, most avalanches occur on slopes of 35 to 45 degrees. Ski resorts with ‘expert’ slopes are a maximum of 35 degrees. The 151 Avalanche area itself rises 1,140 vertical feet with grades exceeding 40% (read Perfect Avalanche Slope Conditions) directly above the highway. The use of snow sails, which aim to disrupt snow drifts and block wind from carrying snow to the slide path, were only partially effective. So the Jackson South Snow Structures project was developed to further reduce the avalanche hazard on the roadway at the 151 Avalanche.