The Caloosahatchee River at sunset. The Caloosahatchee is a manmade river used for drainage and as a navigational canal between Lake Okeechobee and the Gulf of Mexico near Ft. Myers, Florida. This waterway has been a major barrier against northern migration for the Florida panther population. Male panthers have been swimming across the river for decades, but no female panthers were documented north of the Caloosahatchee between 1973 to 2016. Since November 2016, two female Florida panthers have been captured on game cameras north of the Caloosahatchee, giving hope for the recovery of the species into its northern range. September 2018.