Mt. Vernon Canyon is a mountain pass in the Colorado Rockies located on Interstate 70 just east of the Continental Divide. Mt. Vernon Canyon is one of three steep grades on I-70 between Denver and Utah with the Eisenhower Pass and Vail Pass to its west. Mt. Vernon Canyon is made up of two grades with its west grade, commonly called Floyd Hill, and its east grade, commonly called Genesee Hill. The two grades are separated by 6 miles of rolling hills with mild descents between their summits.
Westbound I-70 from the Summit of Floyd Hill has a vertical descent of 627 feet over a distance of 2.1 miles. This descent begins with a large overhead sign warning of the approaching 6% grade. This grade is steep but relatively short by Colorado standards. Near the base of Floyd Hill is a sharp curve on a narrow bridge that has a history truck of roll-overs making this so this is a dangerous descent.
Eastbound I-70 from the Summit of Genesee Hill has a vertical descent of 1,589 feet over a distance of 6.5 miles. The reported grade for this descent is 6% and trucks over 30,000 pounds are restricted to 35 mph. Genesee Hill is the entrance/exit to the Colorado Rockies and is the last grade descent for eastbound I-70.
The Genesee Hill grade levels out near the Denver Metro area around the 260 milepost and has a continued lesser descent to about the 263 milepost.
SUMMIT
Pass Name:
Mt. Vernon Canyon, aka Floyd Hill / Genesee Hill Pass
Traversed by Highway:
I-70
Summit Elevation:
Floyd Hill Westbound: 7,916 ft.
Genesee Hill Eastbound: 7,732 ft.
Summit Milepost:
Floyd Hill Westbound: 247.9
Genesee Hill Eastbound: 253.5
WEST DESCENT
Base Elevation:
7,289 ft
Vertical Distance:
627 ft
Base Milepost:
244
Driving Distance:
2.1 miles
Posted Speed Limit:
55 mph / 45 mph for trucks
Steepest Reported Grade:
6%
Calculated Average Grade:
5.6%
Lowest Advisory Speed:
50 mph at 1.5 miles, 1.9 miles, and 2.2 miles
Number of Lanes:
Starts descent with 3 lands, then to 2 lanes
Number of Advisory Speed Curves:
3
ADVISORY SPEED CURVES
Advisory Speed
Location from Summit
Sign
50 mph
1.5 miles
Left Reverse Curve
50 mph
1.9 miles
Left Curve
50 mph
2.2 miles
Left Reverse Curve
ELEVATIONS
Mile Marker
Elevation
Change in Elevation
Percent Grade
247.9
7,916 ft.
246
7,885 ft.
31 ft.
5.8%
245
7,529 ft.
356 ft.
6.7%
244
7,289 ft.
240 ft.
4.5%
Westbound Floyd Hill Descent
EAST DESCENT
Base Elevation:
6,143 ft.
Vertical Distance:
1,589 ft.
Base Milepost:
260
Driving Distance:
6.5 miles
Posted Speed Limit:
55 mph / 35 mph trucks over 30,000 lbs.
Steepest Reported Grade:
6% at 1.1 miles
Calculated Average Grade:
4.6%
Number of Lanes:
3
Runaway Ramps:
1 at 3.1 miles
ELEVATIONS
Mile Marker
Elevation
Change in Elevation
Percent Grade
253.5
7,732 ft.
254
7,608 ft.
124 ft.
4.6%
255
7,411 ft.
197 ft.
3.7%
256
7,096 ft.
315 ft.
5.9%
257
6,875 ft.
221 ft.
4.1%
258
6,568 ft.
307 ft.
5.8%
259
6,379 ft.
189 ft.
3.5%
260
6,143 ft.
236 ft.
4.4%
RECOMMENDED SPEEDS FROM THE GRADE SEVERITY RATING SYSTEM
MAXIMUM TRUCK WEIGHT (POUNDS)
MAXIMUM SAFE SPEED (MPH)
BRAKE TEMP FROM DECLINE (°F)
BRAKE TEMP FROM EMERGENCY STOP (°F)
TOTAL BRAKE TEMP. (°F)
TOTAL TRAVEL TIME (MIN.)
80,000
30
434
22
456
13.0
75,000
35
454
28
482
11.1
*These speeds are based on an average grade from the summit to the base. Some grade segments may be steeper than the average and require a slower speed.
