24th Street Bridge (Adams County, Illinois)
Built 1936
Concrete bridge over Cedar Creek on IL 96 (24th Street) in Quincy
Open to traffic

Curtis Creek Bridge (Adams County, Illinois)
Built 1899; rehabilitated 1995
Stone arch bridge over Curtis Creek on South 8th Street in Quincy
Open to two-lane traffic

Pier Restaurant Bridge (Adams County, Illinois)
Lost bridge over Quincy Bay at the Quincy riverfront
Bridge no longer standing, but one pier used as foundation for the "Pier Restaurant"

Quincy Bay Railroad Bridge (Adams County, Illinois)
Plate girder bridge over Quincy Bay on the BNSF Railroad in Quincy
Open to railroad traffic

Quincy Bayview Bridge (Adams County, Illinois)
Built 1986 at a cost of $17,230,000
Cable-stayed bridge over the Mississippi River on westbound US 24 at Quincy
Open to two lanes of westbound traffic

Quincy Memorial Bridge (Adams County, Illinois)
Built 1928-1930; rehabilitated 1981
Cantilevered through truss bridge over the Mississippi River on eastbound US 24 at Quincy
Open to two lanes of eastbound traffic

Quincy Railroad Bridge (Adams County, Illinois)
Originally opened Nov. 9, 1868; later rebuilt
Through truss bridge over the Mississippi River on the BNSF Railroad (formerly CB&Q) at Quincy
Open to railroad traffic

Quinsippi Island Bridge (Adams County, Illinois)
Possibly built 1868 by the CB&Q Railroad; later retrofitted for vehicle traffic
Plate girder swing bridge over Quincy Bay providing access to Quinsippi Island Park in Quincy
Open to one-lane traffic