Illinois Route 99
IL 99 highlighted in red
Route information
Maintained by IDOT
Length	32.08 mi[1] (51.63 km)
Existed	1936[2]–present
Major junctions
South end	IL 104 in Chambersburg
Major intersections	US 24 in Mt. Sterling
North end	IL 101 in Huntsville
Location
Country	United States
State	Illinois
Counties	Pike, Brown, Schuyler
Highway system
Illinois State Highway System Interstate US State Tollways Scenic
← IL 98 → IL 100

Illinois Route 99 is a north–south state route in western Illinois. It runs from Illinois Route 104 across the Illinois River and Meredosia, north to Illinois Route 101 in Brooklyn (Schuyler County). This is a distance of 32.08 miles (51.63 km).^[1]

Route description

Illinois 99 runs northwest from Meredosia to Mount Sterling. It enters the Mount Sterling area on Pittsfield Road north of Illinois Route 107. It then overlaps U.S. Route 24 and runs west on Main Street. After about a half mile (.8 km), Illinois 99 then turns north on Cross Street, west on Washington Street, and then back north on Camden Road en route to Camden. Illinois 99 continues north (staying west of the LaMoine River) to Illinois 101 at Brooklyn, its northern termination.^[3]

History

SBI Route 99 had been a route from West Point to Tennessee on local roads, IL 91, IL 61, and US 136. In 1935, IL 99 was dropped from those routes. In 1937, it replaced IL 104 on its current route;^[4] in March 1941, it was announced that IL 99 was extended north to Brooklyn.^[5]

Major intersections

County	Location	mi[6]	km	Destinations	Notes
Pike	​	0.0	0.0	IL 104 – Jacksonville, Quincy
Brown	Mt. Sterling	14.4	23.2	IL 107 south – Pittsfield
		15.1	24.3	US 24 east – Rushville	South end of US 24 concurrency
		15.6	25.1	US 24 west – Quincy	North end of US 24 concurrency
Schuyler	​	32.08	51.63	IL 101 – Bowen
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus