In 1891, the Salish tribe was moved to the current Flathead Reservation under the Treaty of Hellgate.

In 1877, Chief Joseph and his Wallowa band of Nez Perce passed through Ravalli County in their attempt to escape confinement to a reservation; they were captured en route to Canada just south of Havre.

It was named after the Italian Jesuit priest Antony Ravalli, who came to the Bitterroot Valley in 1845.

In terms of ancestry, 28.8% were German, 17.4% were English, 15.9% were Irish, 8.3% were American, 5.7% were Italian, and 5.5% were Norwegian.

Marcus Daly, one of three Butte copper kings, funded logging operations in the Bitterroot Valley.

The valley borders the Selway-Bitterroot Wilderness and offers a wide variety of wildlife, including some of the few remaining wolverine and wolf populations in the contiguous states.

Ravalli County voters have been reliably Republican, opting only one time for the Democratic Party candidate in national elections since 1940 (as of 2024).