The monsters of Templeton / Lauren Groff.

Enhanced descriptions from Syndetics:

"The day I returned to Templeton steeped in disgrace, the fifty-foot corpse of a monster surfaced in Lake Glimmerglass." So begins The Monsters of Templeton , a novel spanning two centuries: part a contemporary story of a girl's search for her father, part historical novel, and part ghost story. In the wake of a disastrous love affair with her older, married archaeology professor at Stanford, brilliant Wilhelmina Cooper arrives back at the doorstep of her hippie mother-turned-born-again-Christian's house in Templeton, NY, a storybook town her ancestors founded that sits on the shores of Lake Glimmerglass. Upon her arrival, a prehistoric monster surfaces in the lake bringing a feeding frenzy to the quiet town, and Willie learns she has a mystery father her mother kept secret Willie's entire life. The beautiful, broody Willie is told that the key to her biological father's identity lies somewhere in her family's history, so she buries herself in the research of her twisted family tree and finds more than she bargained for as a chorus of voices from the town's past -- some sinister, all fascinating -- rise up around her to tell their side of the story. In the end, dark secrets come to light, past and present day are blurred, and old mysteries are finally put to rest. The Monsters of Templeton is a fresh, virtuoso performance that has placed Lauren Groff among the best writers of today.