Climbs

Northern Illinois is flat, so the bar for a climb here is low and that is the point — these are what there is, measured properly rather than argued about. Everything below is within about 165 miles of Chicago.

Steepest average11.2% Pinnacle Road
Sharpest pitch15.4% Heather Drive + Cary Road, over 100 m
Longest2.80 km North Council Hill Road
Measured13 roads, 2026-08-12

Barrington Hillsabout 40 miles from the Loop · the classic NW suburbs loop

Spring Creek Road

minor road · 30 mph/25 mph
Length
200 m
Gain
50 ft
Average
7.6%
Steepest
8.2%
Time
1:10
VAM
777 m/h

Tops out at 850 ft · foot of the climb

Oak Knoll Road

quiet street · 25 mph
Length
275 m
Gain
57 ft
Average
6.4%
Steepest
10.7%
Time
1:23
VAM
757 m/h

Tops out at 827 ft · foot of the climb

Ridge Road

minor road/quiet street · 25 mph
Length
200 m
Gain
41 ft
Average
6.2%
Steepest
9.2%
Time
0:59
VAM
763 m/h

Tops out at 827 ft · foot of the climb

Braeburn Road

quiet street
Length
725 m
Gain
115 ft
Average
4.8%
Steepest
10.7%
Time
2:56
VAM
716 m/h

Tops out at 863 ft · foot of the climb

Cary & Fox River Groveabout 45 miles from the Loop · Fox River valley, McHenry County

Heather Drive + Cary Road

quiet street/minor road · 30 mph
Length
350 m
Gain
88 ft
Average
7.6%
Steepest
15.4%
Time
2:02
VAM
785 m/h

Tops out at 876 ft · foot of the climb

Blackhawk Trail

quiet street · 25 mph
Length
450 m
Gain
109 ft
Average
7.4%
Steepest
10.3%
Time
2:34
VAM
779 m/h

Tops out at 853 ft · foot of the climb

Cary Road

minor road · 30 mph/45 mph/40 mph
Length
200 m
Gain
30 ft
Average
4.5%
Steepest
5.4%
Time
0:46
VAM
708 m/h

Tops out at 863 ft · foot of the climb

Blue Mounds, WIabout 150 miles from the Loop · southern Wisconsin Driftless

Pinnacle Road

quiet street
Length
800 m
Gain
293 ft
Average
11.2%
Steepest
15.2%
Time
6:36
VAM
811 m/h

Tops out at 1132 ft · foot of the climb

Mounds Park Road

minor road · 35 mph
Length
1300 m
Gain
439 ft
Average
10.3%
Steepest
13.9%
Time
9:56
VAM
808 m/h

Tops out at 1421 ft · foot of the climb

Jo Daviess Countyabout 165 miles from the Loop · Galena, the Driftless edge

South Blackjack Road

main road
Length
975 m
Gain
334 ft
Average
10.4%
Steepest
14.3%
Time
7:31
VAM
812 m/h

Tops out at 1040 ft · foot of the climb

West Council Hill Road

quiet street/main road · 35 mph
Length
575 m
Gain
156 ft
Average
8.3%
Steepest
10.9%
Time
3:37
VAM
791 m/h

Tops out at 853 ft · foot of the climb

North Blackjack Road

main road · 45 mph
Length
1275 m
Gain
212 ft
Average
5.1%
Steepest
10.1%
Time
5:23
VAM
721 m/h

Tops out at 906 ft · foot of the climb

North Council Hill Road

main road · 30 mph
Length
2800 m
Gain
250 ft
Average
2.7%
Steepest
10%
Time
8:02
VAM
569 m/h

Tops out at 879 ft · foot of the climb

How these were measured

Road geometry from OpenStreetMap, elevation from the USGS 10 m dataset, sampled every 25 m. The method was checked against a known point before anything else — Rockford came back 716 ft against about 720 ft published — and the Barrington Hills figures agree with the Tuesday/Thursday ride's own published gradients to within a few tenths.

"The climb" means the steepest continuous pitch on that road, not the whole ascent from the valley floor. A stretch that dips in the middle scores worse than the unbroken section inside it, so what you see is the hard bit. Ride up from further down and the numbers get longer and gentler.

Times assume a rider putting out 200 W at 84 kg all in, which is only there so the climbs rank against each other. Put your own numbers into the calculator — it will also tell you whether your lowest gear turns at a cadence you can hold on each of these, which on the steeper ones is the real question.

What have we missed?

This list is short because it was built from a handful of leads, not from local knowledge. If there is a hill you ride that belongs here — or one listed that is unpleasant enough on traffic grounds that it should not be — say so and it goes in. Naming the roads in order is enough; the measuring is automated.