The Gasconade rises in the Ozarks northeast of Seymour in eastern Webster County and flows generally north-northeastwardly through Wright, Laclede, Pulaski, Phelps, Maries, Osage and Gasconade Counties, through portions of the Mark Twain National Forest. It flows into the Missouri River at the town of Gasconade.
In Wright County the river collects the short Woods Fork Gasconade River, which rises in Webster County and flows eastward past Hartville. In Laclede County it collects the Osage Fork Gasconade River, which rises in Webster County and flows northeastward. In Pulaski County it collects the Big Piney River.