Madam Emily Preston and her husband, San Francisco attorney Hartwell Preston settled on a ranch 2 miles northeast of Cloverdale on the northern edge of Sonoma County in 1873. Emily, who diagnosed illnesses and prescribed her own homemade medicines, already had a loyal following of people who swore by her healing powers. Hartwell began preaching and a small community grew up around the Preston mansion. Followers built homes on and around the ranch overlooking the Russian River, and soon the "town" of Preston had its own church, school, train station, general store and hospital. When Hartwell died in 1889, Emily Preston took over the spiritual and day-to-day leadership of the community. At its height Preston consisted of about 150 people. A San Francisco Chronicle reporter in September, 1898 described Emily Preston as "a woman who not only owns a townsite but runs every enterprise of importance in it; who is Mayor and Council and School Board and preacher, who owns the water supply and provides work and wages for the inhabitants, who is their medical advisor and cemetery association and their spiritual guide…"The residents of Preston drifted away after Emily Preston’s death in 1909. Today only a handful of the Preston buildings remain, including the church and several colonist residences on Geysers Road in Cloverdale. Most of the buildings, including Emily Preston’s Italianate mansion, were destroyed in 1988 when a downed power line sparked a wildfire.

Emily and Hartwell Prestons’ new faith was known as the Religion of Inspiration, and followers were known as "Volunteers of Heaven" or "Covenanters." While this religion gradually faded from practice following Emily’s death, it lives on in her book, The Hell and the Heaven. The chapters detail many of Emily and Hartwell Prestons’ spiritual beliefs, which they imparted on their followers. In the preface Preston writes, "The first of this book is what Mr. H. L. Preston [Hartwell] talked in the church…As I have never written or advertised, some might wish to read the book to learn what I have been talking about all these years." Emily Preston suggests at the end of her book that "We have to pay God homage and trust Him, and have our private life right if we want prosperity. We cannot live one thing and talk another. It has to be the straight business, for God has a looking-glass over all the world, and we cannot get away from it."