Season of the Snake by Claire Davis
Years after the tragic death of her first husband, Nance Able remarries and begins a new life in the West with Ned, a school principal whose quiet charm lulls her to contentment. A scientist tracking rattlesnakes in the wilderness of Hell's Canyon, Idaho, Nance courts natural dangers-believing that conquering such risk will protect her from further grief. But at home, she is unaware that her husband's secret proclivities are emerging. When Nance's younger, errant sister Meredith moves to town, Ned can no longer suppress the terrifying mysteries of his past, and the sisters must find the strength together to survive his love.