06/05/2026
Man suffers fatal medical event at Deerfield Lake, June 4, 2026. At approximately 10:30 a.m. emergency responders were dispatched to Deerfield Lake in Pennington County following a report of an individual in distress.
First responders located an adult male, identified as Terry Olson, 68 years old from Brookings, South Dakota. Despite response efforts of emergency personnel, Mr. Olson was pronounced deceased at the scene. Preliminary information indicates the death may have resulted from a medical emergency.
Responding agencies included Hill City Ambulance, Hill City Volunteer Fire Department, Pennington County Search and Rescue, Rapid City/Pennington County Water Rescue Team, Rapid City Fire Department, Rochford Volunteer Fire Department, South Dakota Game Fish, Black Hills Life Flight and Parks and the Pennington County Sheriff's Office.
The Pennington County Sheriff's Office extends its sincere condolences to Mr. Olson's family, friends, and loved ones during this difficult time. At this time, there is no indication of suspicious circumstances. The incident remains under review, and no additional information is available for release.