Captured Hummingbird. Gabriel Hawke Novel, #15

Fish and Wildlife State Trooper Hawke has tracked killers through the wild-but this time the clock is his deadliest enemy. When Hawke's partner, Dani, calls with a desperate plea to find her newly married cousin and young daughter who have vanished without a trace, he can't say no. The trail quickly leads to the violent first husband-a drunk who knows the Idaho wilderness better than most men know their own homes.
Hawke finds the man's remote hunting shack and makes a chilling discovery: the ex-husband is already dead. Dani and Hawke uncover disturbing evidence. Corruption in the casino, exploitation in the sheriff's office, and something more sinister that caused the mother and child's sudden disappearance.