At the Rendezvous by Sara Dahmen

Fell Madson lost the woman he loved to another man. Surly and taciturn by nature, he's known for his iron work, his size, and his anger. Fell has no intention of letting himself be fooled by another woman's promise. At the spring rendezvous, he only wants to work his forge and keep to himself.

Helen Parrier was abandoned by her husband and managed three small sons and the fur traps all winter alone. She believes herself unworthy and simply wants to make ends meet without selling herself to the highest bidder to do so. When spring arrives, everyone in the Missouri Territory descends onto the prairie to barter and reconnect. Helen knows she must trade her pelts to have a chance at survival.

When Fell and Helen meet, the attraction is blinding. But Fell is still hostage to memories of his former betrothed and Helen's expectation is that she will always be the woman left behind. In the middle of painful revelations and loss, Fell and Helen try to find a way to one another before the wilderness rips them apart.