Rosetown RCMP have completed their investigation into the multi-vehicle collision that left six people dead back on June 29.

They determined that a 71-year-old woman from Swift Current - who was the lone occupant of a northbound SUV on Highway 4 - crossed over into the southbound lane, causing the head-on collision with another SUV.

The five others that died were a family from around Rosetown - parents Troy and Carissa Gasper, and children Kael, Shea, and Maks.

Investigators weren't able to determine, with certainty, why the 71 year old crossed into the southbound lane, but they did rule out alcohol as a factor.