Fort Zumwalt Park is a park in O'Fallon, Missouri, that features the rebuilt homestead fort of Jacob Zumwalt. The park's total area is 48 acres with 4-acre Lake Whetsel, a picnic pavilion, a shelter house, and a children's playground with equipment. The lake is open for fishing from February though October. Fort Zumwalt Park hosts O'Fallon's annual Celebration of Lights, a drive-through display of light decorations, every Christmas season, and is home to the St. Charles Model Railroad Club.