Honor my Word: A Historical Western Romance (Rancher's Word #5)
Linda K. Hubalek

Rancher Luther Tucker would prefer never to set foot off the Cross C Ranch, but he promised his grandfather he’d accompany his sister on a trip to Yellowstone National Park. Luther would never guess it would turn into a two-week camping trip in the wilderness of Montana with only a female guide while dodging bison, bears, and forest fires.
Myreta Hamman took her deceased father's place as a guide on a camping trip through Yellowstone because she grew up in the wilderness, and she’d already used the pre-paid payment to bury her father.
Stuck with honoring their word to others, Luther and Myreta find hard truths about themselves and each other as they face tremendous challenges in the wilderness while falling in love with each other