Drives Illinois Iowa and Illinois
Great River Road: Alton to Grafton
IL 100, Great River Road · Alton → Pere Marquette State Park
The drive
Illinois Route 100 leaves downtown Alton and follows the east bank of the Mississippi to Grafton, where the Illinois River joins it, then continues to Pere Marquette State Park: 19 miles, flat, with mostly gentle curves. Route 100 is part of the Great River Road here and of the Meeting of the Great Rivers Scenic Byway.
The Piasa Bird mural is on the limestone bluffs over the river in Alton. French explorers recorded the original painted figures in 1673; the mural visible today is a 22 by 48 foot painting completed in 1999. Grafton is the oldest city in Jersey County, and the Sam Vadalabene Bike Trail runs nearby. The drive ends at Pere Marquette State Park, 8,050 acres on Route 100 with a lodge built by the Civilian Conservation Corps in the 1930s.
Along the way
- Alton
- Piasa Bird
- Grafton
- Pere Marquette State Park
Good to know
- Route 100 is susceptible to flooding in high water, so check conditions after heavy rain or a river rise.
- Grafton is known for bald eagle watching in winter.
- Cyclists use the Sam Vadalabene Bike Trail, which is separate from the road.
Open all year, weather permitting. Roads close for snow, fire, storms and repairs: before you set off, check IDOT Getting Around Illinois.
Questions about this drive
How long does the Great River Road from Alton to Grafton take?
Illinois Route 100 from Alton to Pere Marquette State Park is 19 miles and takes about 25 minutes.
Does the Great River Road in Illinois flood?
Yes. Illinois Route 100 is described as susceptible to flooding during high water along the river.
Where is the Piasa Bird?
The Piasa Bird mural is on the limestone bluffs overlooking the Mississippi River in Alton, along this drive.
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More drives near here
Distance, time, elevation, curves and intensity are from Carve's route. Checked 2026-10-28.