Innocent Hearts by Radclyffe

In 1860's Montana Territory, Kate Beecher, a young woman from Boston, faces the hardships and hard choices of life on the frontier. Just eighteen and quietly struggling against the social constraints of the era, Kate meets a woman who fires first her imagination, and then her dreams. Jessie Forbes, a fiercely independent rancher, finds in Kate the passion she never knew she had been missing. This is the story of their struggle to love in a land, and time, as cruel as it was beautiful.