Through interactions with Iroquois Indians between 1812 and 1820, the Bitter Root Salish Indians leaned about Christianity and Jesuit Missionaries (blackrobes) that worked with Indian tribes teaching about agriculture, medicine, and religion. Interest in these “blackrobes” grew among the Salish and, in 1831, four young Salish men were dispatched to St. Louis, Missouri to request a “blackrobe” to return with them to their homeland of present day Stevensville. The four Salish men were directed to the home and office of William Clark (of Lewis and Clark fame) to make their request. At that time Clark was in charge of administering the territory they called home. Through the perils of their trip two of the Indians died at the home of General Clark. The remaining two Salish men secured a visit with St. Louis Bishop Joseph Rosati who assured them that missionaries would be sent to the Bitter Root Valley when funds and missionaries were available in the future.
Again in 1835 and 1837 the Bitter Root Salish dispatched men to St. Louis to request missionaries but to no avail. Finally in 1839 a group of Iroquois and Salish met Father Pierre Jean DeSmet in Council Bluff, IA. The meeting resulted in Fr. DeSmet promising to fulfill their request for a missionary the following year.
DeSmet arrived in present day Stevensville on September 24, 1841 and called the settlement St. Mary’s. Construction of a chapel immediately began followed by other permanent structures including log cabins and Montana’s first pharmacy.
In 1850 Major John Owen arrive in the valley and set up camp south of St. Mary’s. In time, Major Owen established a trading post and military strong point named Fort Owen, which served the settlers, Indians, and missionaries in the valley.
Both St. Mary’s Mission and Fort Owen still have permanent structures that stand today in present day Stevensville denoting its historical past starting in 1841.
The name of the settlement was changed from St. Mary's to Stevensville in 1864 to honor territorial govenor Isaac Ingle Stevens. Luther E. Stanley says "When Isaac Ingle Stevens was ordered to Fort Owen in 1853, he came to what he supposed would be a military fort but much to his surprise, it was a trading post. General Stevens, for the past year, had been in charge of military operations and Indian affairs in the Northwest Territory...he moved his government and military material to Fort Owen. This fort became the territorial capital in 1853 and served that until 1858, when Stevens was called back to active duty with the Union Army. He was killed in action in 1862 at Chantilly....Stevens laid out a new town near the ruins of St. Mary's Mission and Fort Owen...It was named Stevensville in his honor and authorized by President Lincoln on May 12, 1864."
"Flanked by the Bitterroot and Sapphire mountains, the small, historic town in the Bitterroot Valley offers beautiful views, outdoor recreation and watchable wildlife. The Bitterroot Mountain Range, just west of Stevensville, is the longest single mountain range in the Rocky Mountains.
There were 652 households out of which 29.4% had children under the age of 18 living with them, 46.0% were married couples living together, 10.7% had a female householder with no husband present, and 40.8% were non-families. 35.6% of all households were made up of individuals and 16.0% had someone living alone who was 65 years of age or older. The average household size was 2.27 and the average family size was 2.93.
In the town the population was spread out with 25.3% under the age of 18, 9.0% from 18 to 24, 24.9% from 25 to 44, 20.1% from 45 to 64, and 20.8% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 89.9 males. For every 100 females age 18 and over, there were 85.0 males.
The median income for a household in the town was $27,951, and the median income for a family was $34,583. Males had a median income of $29,327 versus $20,729 for females. The per capita income for the town was $14,700. About 10.4% of families and 12.8% of the population were below the poverty line, including 13.3% of those under age 18 and 9.7% of those age 65 or over.