The Counterfeit Bride — Nancy J. Parra

Lillian Picken discovers the perfect solution for the problem of being a female entrepreneur in the 1870s. She invents a husband, Donovan West, and convinces the townsfolk that he will return as soon as his army commission is up. The ruse works, until the day a man comes to town claiming to be Donovan West.

Secret Service agent Patrick Donovan must ferret out a counterfeit ring in the Silverton area. Donovan's search for the perfect cover ends at the discovery of Lillian's secret. He takes the place of her pretend husband.

But the deep attraction he feels for her begins to complicate things. Not only has Donovan's mission put Lillian in danger, but he has vowed never to marry again and when the job is over, he will return to Washington D.C. for his next assignment. Lillian claims not to care where he goes, but will cracking the case leave them both with a broken heart?