According to Assumption Parish Sheriff Mike Wauespack, Guist suffered a fall in a boat shortly after it launched into the Belle River in St. Martin Parish on Monday morning. Witnesses said Guist was having what appeared to be seizures, but attempts to resuscitate him were unsuccessful.
The cause of death is unknown.
"We are extremely saddened to report that our friend and beloved member of the Swamp People family, Mitchell Guist, has passed away earlier today," The History Channel said in a statement. "Mitchell passed on the swamp, doing what he loved. We appreciate your respect for the Guist family's privacy and hope you join us in sending our thoughts and prayers to his brother, Glenn, and the rest of the Guist family."
A History Channel spokesperson added that all episodes of Swamp People would air as scheduled, but the show is working on a way to "honor his memory."