Major Highway Grades in the United States

State or Territory

Route

Location

Summit Elevation

Coordinates

Length

Maximum Grade

Runaway Truck Ramps

Comments

Arizona

Interstate 17

Southbound from Munds Park

6378 ft (1944 m)

34°48'35.7"N 111°36'21.2"W

18 miles (29.0 km)

6%

1

Arizona

Interstate 17

Northbound into Verde Valley

4723 ft (1440 m)

34°31'58.6"N 111°57'49.9"W

7 miles (11.3 km)

6%

1

Arizona

U.S. Route 60 / State Route 77

Eastbound into Salt River Canyon

4830 ft (1472 m)

33°46'10.6"N 110°30'38.8"W

5 miles (8.0 km)

6%

1

Arizona

U.S. Route 60 / State Route 77

Westbound into Salt River Canyon

4927 ft (1502 m)

33°49'39.0"N 110°27'23.9"W

5 miles (8.0 km)

6%

0

Arizona

State Route 89A

Southbound into Oak Creek Canyon

6545 ft (1995 m)

35°02'19.6"N 111°44'00.7"W

3 miles (4.8 km)

7%

0

Multiple sharp switchbacks

California

Interstate 5

Grapevine; Northbound from Tejon Pass

4144 ft (1263 m)

34°52'19.7"N 118°53'21.8"W

5 miles (8.0 km)

6%

2

California

Interstate 5

Five Mile Grade; Sounthbound from Violin Summit

2589 ft (789 m)

34°33'38.2"N 118°40'48.9"W

5 miles (8.0 km)

5%

0

Unique left-hand driving configuration with crossovers and top and bottom of grade

California

Interstate 8

In-Ko-Pah Gorge; Eastbound from Jacumba Hot Springs

3000 ft (914 m)

32°38'13.2"N 116°06'51.6"W

7 miles (11.3 km)

6%

1

Strong wind hazard. Westbound traffic ascends Devil's Canyon up to 1.5 miles away.

California

State Route 108

Eastbound from Sonora Pass

9624 ft (2933 m)

38°19'39.6"N 119°38'12.4"W

12 miles (19.3 km)

26%

0

Subject to winter closures. Trucks over 38 feet from kingpin to rear axle prohibited, over 30 feet not advised.

California

State Route 4

Eastbound from Ebbets Pass

8736 ft (2663 m)

38°32'40.1"N 119°48'42.9"W

25 miles (40.2 km)

24%

0

Single lane with turnouts. Not maintained in winter. Vehicles over 25 feet long not advised.

Colorado

Interstate 70

Clear Creek Canyon, eastbound from Eisenhower Tunnel

11,112 ft (3387 m)

39°40'54.0"N 105°53'39.4"W

12 miles (19.3 km)

6%

1

Highest elevation on U.S. Interstate Highway system

Colorado

Interstate 70

Eastbound from Genesee Park

7740 ft (2359 m)

39°42'36.0"N 105°17'39.8"W

5 miles (8.0 km)

6%

1

Colorado

Interstate 70

Westbound from Eisenhower Tunnel

11,112 ft (3387 m)

39°40'44.2"N 105°56'07.7"W

6 miles (9.7 km)

7%

2

Highest elevation on U.S. Interstate Highway system

Colorado

U.S. Route 160

Eastbound from Wolf Creek Pass

10,857 ft (3309 m)

37°28'58.7"N 106°47'59.8"W

8 miles (12.9 km)

6%

0

Includes a snow shed and the Wolf Creek Pass Tunnel

Colorado

U.S. Route 160

Westbound from Wolf Creek Pass

10,857 ft (3309 m)

37°28'58.7"N 106°47'59.8"W

9 miles (14.5 km)

7%

2

Hairpin curve 6 miles (9.7 km) from summit

Colorado

U.S. Route 550 (Million Dollar Highway)

Northbound from Red Mountain Pass to Ouray

11,018 ft (3358 m)

37°53'55.0"N 107°42'43.7"W

13 miles (20.9 km)

8%

0

Narrow 2-lane highway with sharp curves and unguarded dropoffs, frequent avalanches

Colorado

U.S. Route 550 (Million Dollar Highway)

Southbound from Red Mountain Pass

11,018 ft (3358 m)

37°53'55.0"N 107°42'43.7"W

10 miles (16.1 km)

8%

0

Narrow 2-lane highway with sharp curves and unguarded dropoffs, frequent avalanches

California

Interstate 15

Southbound from Cajon Summit

4260 ft (1298 m)

32°38'13.2"N 116°06'51.6"W

4 miles (6.4 km)

6%

1

California

Interstate 80

Eastbound from Donner Summit

7227 ft (2203 m)

39°20'29.5"N 120°20'24.0"W

5 miles (8.0 km)

6%

0

Subject to extreme snowfall

California

Interstate 80

Westbound from Donner Summit

7227 ft (2203 m)

39°20'29.5"N 120°20'24.0"W

2 miles (3.2 km)

5%

0

Subject to extreme snowfall

North Carolina

Interstate 26 / U.S. Route 74

Eastbound from Howard Gap

1900 ft (580 m)

35°14'57.5"N 82°16'29.7"W

3 miles (4.8 km)

6%

0

North Carolina

Interstate 40 / U.S. Route 70

Old Fort Mountain, eastbound from Swannanoa Gap

2657 ft (810 m)

35°37'03.2"N 82°15'42.6"W

6 miles (9.7 km)

6%

3

Mandatory brake check at summit

Oregon

Interstate 5

Northbound from Siskiyou Summit

4310 ft (1314 m)

42°03'43.1"N 122°36'21.4"W

7 miles (11.3 km)

6%

2

Highest point on Interstate 5

Oregon

Interstate 5

Southbound from Siskiyou Summit

4310 ft (1314 m)

42°03'43.1"N 122°36'21.4"W

7 miles (11.3 km)

6%

1

Highest point on Interstate 5

Oregon

Interstate 84

Cabbage Hill; Westbound from Deadman Pass

3609 ft (1100 m)

45°36′03″N 118°30′14″W

6 miles (9.7 km)

6%

1

Washington

U.S. Route 2

Westbound from Stevens Pass

4061 ft (1238 m)

47°44'46.8"N 121°05'18.2"W

7 miles (11.3 km)

6%

0

40 MPH hairpin curve 4 miles from summit

Washington

U.S. Route 12

Westbound from White Pass

4500 ft (1372 m)

46°38'14.8"N 121°23'33.8"W

4 miles (6.4 km)

6%

1

Wyoming

U.S. Route 14

Shell Canyon, eastbound from Granite Pass

9033 ft (2753 m)

44°38'23.6"N 107°30'11.9"W

11 miles (17.7 km)

6%

1

Wyoming

U.S. Route 14

Eastbound from Sibley Lake

7912 ft (2411 m)

44°47'26.3"N 107°23'37.3"W

12 miles (19.3 km)

8%

0

Mandatory brake check at summit. Multiple hairpin curves; trucks restricted to 20 MPH

Wyoming

U.S. Route 14A

Medicine Wheel Passage, westbound from Burgess Junction

9083 ft (2768 m)

44°48'28.8"N 107°52'56.5"W

13 miles (20.9 km)

10%

3 ramps and one brake cooling turnout

Closed winters; Mandatory brake check at summit

Wyoming

U.S. Route 212 (Beartooth Highway)

Eastbound from Beartooth Pass

10,947 ft (3336 m)

44°58'08.8"N 109°28'16.5"W

14 miles (22.5 km)

10%

0

Closed winters. Commercial traffic prohibited

Wyoming and Montana

U.S. Route 212 (Beartooth Highway)

Westbound from Beartooth Pass

10,947 ft (3336 m)

44°58'08.8"N 109°28'16.5"W

18 miles (29.0 km)

10%

0

Closed winters. Commercial traffic prohibited

Wyoming

State Route 22 (Teton Pass Highway)

Eastbound from Teton Pass

8431 ft (2570 m)

43°29'50.8"N 110°57'19.2"W

5 miles (8.0 km)

10%

2 (one with mechanical arrestor system)

Subject to winter closures at Idaho state line