The second Indian Agency on the Blackfeet Reservation was built in 1879 at Old Agency, at the bend in the Flathead River. Agent John Young moved the buildings from Upper Badger Creek with help from the Blackfeet Indians. Both men and women dug cellars, hauled stone and mixed mortar. The women covered the exterior with lime from Heart Butte. The Indians called it "Old Ration Place" after the government began issuing rations.

Arlee was named after the Salish leader Arlee.[8] In October 1873, he moved a small group of his people from the Bitterroot Valley, which was designated a "conditional reservation" in the 1855 Hellgate Treaty, to the Jocko Agency[9] (

Having two Boulder Rivers in Montana often leads to confusion, with some descriptions mistakenly combine the two. The Boulder River in Southwest Montana begins in Jefferson County, northwest of the town of Boulder. The river flows through a canyon along Interstate 15, at the town, it loops to the south, leisurely meandering through the Boulder Valley until it joins the Jefferson near Cardwell. In late summer, irrigation needs reduce the river's already meager water still further, making fishing and floating difficult.