A 77-year-old Mendota Heights man who vanished near Prescott Island on the Mississippi River has been found dead, ending a weeklong search that stretched across the Minnesota-Wisconsin border. Michael William Robinson was last seen the evening of July 28 wearing a yellow shirt and a silver bracelet, and his unoccupied boat was later discovered near the island, prompting an intensive multi-agency response.
According to the KSTP, Robinson was reported missing near Prescott Island by the Dakota County Sheriff's Office, and ground and water searches turned up his empty boat close to the island before he was found. Dakota County officials have since confirmed his body was located on August 4, downstream from where the boat was recovered, according to the Dakota County Sheriff's Office. Robinson was ultimately found dead in Pierce County, Wisconsin, per KSTP's reporting.
A Bi-State Search Effort Near the River Confluence
Prescott Island sits in the Mississippi River near Hastings, Minnesota, about 2.4 miles west-northwest of Prescott, Wisconsin, close to where the St. Croix and Mississippi rivers meet, as reported by Apple Valley Patch. That geography made for a complicated search zone, and the weeklong effort drew in specialized dive, drone, and special operations teams from Dakota County alongside the Pierce County Sheriff's Office, the Wisconsin Department of Natural Resources, Northstar Search and Rescue, and fire departments from Hastings and Prescott, the outlet noted.
Dakota County Sheriff Joe Leko addressed the outcome directly. “This is not the outcome any of us had hoped for. Our hearts are with Michael's family and loved ones during this incredibly difficult time,” Leko said, according to KSTP's reporting on the case.
No Signs of Foul Play, Investigation Continues
Preliminary findings released by the Dakota County Sheriff's Office indicated no signs of foul play or suspicious circumstances surrounding Robinson's death, per KROC-AM News. That assessment is preliminary, and a final determination on the exact cause of death would depend on official medical findings that have not yet been reported.
A Difficult Summer on Minnesota Waterways
Robinson's death adds to what has already been a rough stretch for boaters in the state. The Minnesota Department of Natural Resources recorded four fatal boating accidents through late June, up from three during the same period in 2025, according to CBS News, which cited hot weather and heavy river traffic as contributing factors cited by state officials.
Life jacket use remains a central safety concern for regulators. A 2026 water safety alert from the Minnesota Department of Human Services noted that none of the people who died in boating-related incidents in the state in 2024 were wearing a life jacket. State law has also tightened in recent years — as of July 1, anyone born after June 30, 2000, must hold a boating safety certification to operate a motorized watercraft on Minnesota's public waters, per the Minnesota Department of Natural Resources. The agency also reports that operating under the influence factors into roughly 30 percent of the state's fatal boating accidents.
Across the river in Wisconsin, the risks look similarly steep. The Wisconsin Department of Natural Resources reported 14 recreational boating fatalities in 2024, with drowning accounting for nearly 80 percent of the state's fatal boating incidents. With Prescott Island sitting directly along the border the two states share, Robinson's case underscores how emergencies on that stretch of river routinely require cooperation from agencies on both sides.
