«The Edge of Winter» by C.J.Box

An e-book bundle of the first three Joe Pickett novels
Open Season:There's nothing unusual about the sound of a gunshot in Twelve Sleep. Here in remotest Wyoming, where elk roam the pine forests and cougars prowl the mountains, everyone owns a gun. But when Joe Pickett hears two sharp cracks ring out months before hunting season, it's his job to investigate the first murder he's ever encountered. Battling grudge-holding neighbours, corrupt officials and out-of-town activists, Joe begins to unravel a mystery that threatens the life and the family he loves.
Savage Run:Game warden Joe Pickett is called to a bizarre crime scene deep within the forests of Twelve Sleep County, Wyoming. The case is wrapped up too quickly, and Joe's search for the truth leads him ever deeper into the wilderness of the Bighorn Mountains. With two unlikely allies at his side, and two hired killers on his heels, Joe can't avoid the legendary Savage Run – a treacherous, isolated canyon with no crossing…
Winterkill:It's an hour away from darkness, a bitter winter storm is raging, and Joe Pickett is deep in the forest edging Battle Mountain, shotgun in his left hand, his truck's steering wheel handcuffed to his right – and Lamar Gardiner's arrow-riddled corpse splayed against the tree in front of him. Lamar's murder and the sudden onslaught of the snowstorm warn: Get off the mountain. But Joe knows this episode is far from over. Somewhere in the dense timber, a killer draws his bowstring – with Joe as his prey…