A half-brother (by his father's second wife Brigitte Saucier) was François Chouteau, a trader who became one of the first European-American settlers of Kansas City, Missouri.

[2] Pierre Chouteau followed in the family footsteps by starting a trade with the Osage tribe at age 15.

[4] In 1847 Pierre and his brother Auguste established Fort Benton in present-day Chouteau County, Montana as the last fur trading post on the Upper Missouri River.

[5] A portion of the Pierre Chouteau and Family Papers are available for research use at the Minnesota Historical Society.

They consist of original, photostatic copies from the Missouri Historical Society, and typed transcripts of letters between Pierre Chouteau, Henry Chouteau, Ramsay Crooks, George Davenport, Hercules L. Dousman, Kenneth McKenzie, Henry M. Rice, Joseph Rolette, Henry H. Sibley, Joseph M. Street and others as well as contracts, accounts, and other related documents concerning the fur trade, fur companies, the Dakota, Sauk, and Fox Indians, and similar matters.