This place is a frog’s nightmare. Bank-eroded trees complicate the shoreline in various stages of decay, providing perfect ambush spots for finned predators. Farther out in this slow-moving river, lily pads bejeweled with yellow flowers contrast deepwater pockets the color of tea. Milfoil and other spindly weeds crowd the channel, which at its deepest reaches only four or five feet. All is peaceful now. I’m hoping to change that. I’m chucking a...