Baring the Thorn by Sarah Blake

In the distant future, only men are left on the Earth’s surface, until a bunker of women wakes up…

As the only nurse of the growing Mountain Tribe, Samara is running herself into the ground. After the latest close call, she knows that she needs to reach a secret cache of medical supplies out in the wild or any future disaster could end in death.
Her plan is simple: obtain a willing guide through the post-apocalyptic forest, find the cache, bring it back to camp, and, under no circumstances, fall in love with the tribe’s brooding leader.
When Samara asks the tribe hunters for help on a critical mission, Thorn can think of no better guide than himself. He’s capable, he’s efficient, he’s a strong leader, and he can’t stand the thought of her disappearing into the wilderness with another man.
Thorn has always considered himself reserved, yet everything about Samara brings his guard down. Telling her how he really feels for her could be dangerous. But telling her the truth about the world could destroy everything…

This steamy romance is the third book in The Mountain Tribe series of science fiction romance novels. It is a complete story and can be read as a standalone. However, The Mountain Tribe is best enjoyed in the series order.