Montana Gold by Diane Darcy

Confronted by her fiancé’s pregnant mistress, heiress Lucy Rickman decides she’s not interested in marriage, after all. Encouraged by her headstrong grandmother, she heads west, glad for the chance to get away from lying men, and hoping for an adventure. She will now have the chance to use her education, avoid men and marriage, and find true, honest friends in Butte, Montana.

Being both a bachelor and a millionaire has Boone Jackson running for cover! His mother wants him to find a wife! Like… yesterday!

He’s not interested, until the new schoolmistress shows up in town, that is. When she mistakes him for the local handyman, he finally has the perfect opportunity to see if a beautiful girl could want him for himself, rather than for what he can provide
But if Lucy finds out, will she be able to move past his lie? Or will she leave him behind in the dusty mining town forever?