Just a few miles from the Big Sioux River and Iowa’s westernmost point lies a marker recalling the late American frontier. (Photo taken July 20, 2012. That’s not a color problem, it’s a drought problem.)
Fort Brule was established in 1861 but abandoned less than a decade later, as this Sioux Falls Argus-Leader article from 1954 explains. (That link also includes the text on the monument.) Iowa soldiers served at the fort one year. This marker is on SD 50 about a mile and a half east of SD 11 (old US 77).
This marker reminds us that while Iowa became a state in 1846, the western reaches of the state and points farther west did not see extensive white settlement until decades later.