Great Loop bridge planning reference

100th Street Bridge

100th Street Bridge on Calumet Rivernear Chicago, IL; closed clearance about 18.5 ft. Critical low Calumet bridge.

41.71300000, -87.56000000

Drawbridge / movable
WaterwayCalumet River
Route SegmentIllinois / Chicago
Route VariantInland Rivers / Chicago or Cal-Sag
State / ProvinceIL
Nearest CityChicago
Mile MarkerRM 331.6
Bridge TypeBascule
Source Confidencemedium

What Boaters Should Know

100th Street Bridge on Calumet Rivernear Chicago, IL; closed clearance about 18.5 ft. Critical low Calumet bridge.

Clearance And Opening Details

Vertical Clearance Closed18.50 ft
Vertical Clearance OpenNot verified
Horizontal Clearance197.90 ft
VHF ChannelNot verified
PhoneNot verified
Last Verified2026-06-08
Bridge contact information has not been verified yet. Confirm current opening procedures before transit.
Verify against current water level / bridge gauge before transit.

Opening / Contact Notes

Opening Schedule
Bascule; verify opening/status.
Operator / Contact
Not verified

Navigation And Regulatory Notes

Air Draft Notes
Closed/air-draft clearance: 18.5 ft. Datum/reference: Low Water Datum Lake Michigan; IGLD 1985. Clearance band: Route-limiting / Critical
Navigation Notes
Bascule; verify opening/status. Sub-20-ft closed clearance. Closed/air-draft clearance: 18.5 ft. Datum/reference: Low Water Datum Lake Michigan; IGLD 1985. Clearance band: Route-limiting / Critical Bascule; verify opening/status.
Regulatory Notes
Bascule; verify opening/status. Sub-20-ft closed clearance.

Planning Considerations

Confirm your vessel air draft, current water levels, bridge signage, official charts, bridge schedules, Local Notices to Mariners, and any VHF or phone procedures before approaching this bridge. If the bridge is movable, build extra time into your route plan for opening windows, traffic, restrictions, weather, and communication delays.

Planning awareness only: Bridge information is provided for planning awareness only. Always verify current bridge status, clearance, water levels, bridge schedules, opening restrictions, Local Notices to Mariners, bridge signage, and official charts before transit. FloatPlanWizard is not a navigation authority.