Rabbit Ears Pass is a high mountain pass in the Colorado Rockies along the Continental Divide. Rabbit Ears' west summit is located on U.S. Highway 40, 14 miles east of Steamboat Springs, Colorado. Rabbit Ears' east summit is approximately 8 miles from the west summit, and U.S. Highway 40 between the east and west summits consists mainly of rolling hills with some short grade descents. U.S. Highway 40 is the northern route across the state of Colorado and connects I-70 with Salt Lake City, Utah. U.S. Highway 40, on both sides of Rabbit Ears Summit is a steep, windy descent. Rabbit Ears Pass receives a large amount of snow in the winter and may have chain restrictions for commercial trucks or be closed for snow control.
Westbound U.S. 40 from the Rabbit Ears Summit has a vertical descent of 2,467 feet over a distance of approximately 7.5 miles. The reported grade for the westbound descent is 7%. The calculated average grade for this descent is 6.2%, and the steepest measured grade is 7.2%. Westbound Rabbit Ears Pass has numerous advisory curves with the lowest being marked at 40 mph, at about 5.8 miles west of the west summit.
Eastbound U.S. 40 from the Rabbit Ears Summit has a vertical descent of 1,197 feet over a distance of approximately 5.5 miles.
The eastbound descent is much milder than the westbound with a 4.1% average grade and four advisory curves with only one having an advisory speed (45 mph). The summit of Muddy Pass is approximately 3 miles east of the east summit Rabbit Ears Pass. Or stated differently, Muddy Pass is about halfway down the east side of Rabbit Ears Pass. Muddy Pass is effectively the pass between the junction of U.S. 40 and Colorado State Highway 14, and therefore, the eastbound descent from Muddy Pass is simply the continuation of the eastbound descent from Rabbit Ears Pass.
SUMMIT
Pass Name:
Rabbit Ears Pass / Muddy Pass
Traversed by Highway:
US-40
Summit Elevation:
West Summit 9,400 ft.
East Summit 9,426 ft.
Summit Conditions:
Brake checks on East and West Summit
Summit Milepost:
146.5 West Summit
154 East Summit
WEST DESCENT
Base Elevation:
6,933 ft
Vertical Distance:
2,467 ft
Base Milepost:
139
Driving Distance:
7.5 miles from summit
Posted Speed Limit:
50 mph
Steepest Reported Grade:
7%
Calculated Average Grade:
6.2%
Lowest Advisory Speed:
40 mph at 5.8 miles
Number of Lanes:
2 up, 1 down
Number of Advisory Speed Curves:
10
Runaway Ramps:
1 at 4.1 miles
Number of Brake Check Stations:
1 at West Summit
ADVISORY SPEED CURVES
Advisory Speed
Location from Summit
Sign
45 mph
0.5 miles
Left Curve
45 mph
1.5 miles
Right Curve
45 mph
3.6 miles
Right Curve
45 mph
4.0 miles
Right Curve
45 mph
4.2 miles
Left Curve
None
4.7 miles
Right Curve
45 mph
5.2 miles
Left Reverse Curve
40 mph
5.8 miles
Left Curve
45 mph
6.0 miles
Right Curve
None
6.7 miles
Left Curve
ELEVATIONS
Mile Marker
Elevation
Change in Elevation
Percent Grade
146.5
9,400 ft.
146
9,258 ft.
142 ft.
5.3%
145
8,909 ft.
349 ft.
6.6%
144
8,606 ft.
303 ft.
5.7%
143
8,242 ft.
364 ft.
6.8%
142
7,883 ft.
359 ft.
6.7%
141
7,502 ft.
381 ft.
7.2%
140
7,196 ft.
306 ft.
5.7%
139
6,933 ft.
263 ft.
4.9%
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
13
462
4
466
39.98
75,000
15
471
5
476
32.0
70,000
18
483
7
490
26.7
65,000
22
484
9
493
21.8
60,000
29
481
15
496
16.6
55,000
34
478
19
497
14.1
50,000
50
424
38
462
9.6
*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.
