Seven people died in a devastating collision the evening of May 1 along a major route into Yellowstone National Park in Idaho.

The crash occurred around 7:15 p.m. on U.S. Highway 20, close to Henry’s Lake in Fremont County, Idaho, Buckrail reported. 

According to information from the Idaho State Police (ISP), a Dodge Ram pickup truck struck a Mercedes passenger van that was transporting 14 individuals on a tour. The impact proved fatal for six passengers inside the van and the driver of the pickup truck. The cause of the crash is still under investigation.

“Due to the magnitude of the incident and the ongoing process of notifying the next of kin, no names, ages, hometowns or nationalities have been released,” ISP said in a May 2 statement. 

The crash prompted a nearly seven-hour closure of the highway as emergency crews conducted rescue efforts and investigators began their work. This stretch of road is heavily trafficked by tourists entering Yellowstone through its west entrance.