The Musone originates in the municipality of Gagliole, at around 775 meters above sea level, from the convergence of two valleys and continues eastwards to flow into the Adriatic Sea a few kilometers away. In Latin times, it was known as Misco; during the Middle Ages and the Renaissance, the stretch of the river near the confluence with the Aspio marked the border between the Republic of Ancona and the Marca Fermana. At this point, the river can generally be crossed without difficulty.