SPEARFISH, S.D. – A 56-year-old Spearfish man died Sunday from injuries sustained in a single-vehicle crash Saturday evening near Spearfish, according to authorities.

The driver, whose name is being withheld pending notification of family members, was involved in the wreck around 5:45 p.m. Saturday, July 25, on Interstate 90 at mile marker 19, located 1 mile east of Spearfish.

Preliminary crash information indicates the driver of a 1995 Harley Davidson FLHTCU was traveling westbound on I-90 when he began to lose control of the motorcycle and laid it down. The driver became separated from the vehicle in the process. Authorities confirmed the driver was not wearing a helmet.

Following the crash, the driver was transported to a hospital in Spearfish before being transferred to a Rapid City hospital for further treatment, where he died from his injuries on Sunday, July 26.

The South Dakota Highway Patrol, an agency of the South Dakota Department of Public Safety, is investigating the crash, and all released information remains preliminary.