Mount Graham (Swift Trail, AZ-366)
Climb · Tucson & the Sky Islands
Checked
part of: Hairpin heaven: the most switchbacks on one climbpart of: The vertical kilometre clubpart of: Roads built as statementspart of: Roads to the telescopespart of: The mountains America races up
Mount Graham (Swift Trail, AZ-366) is a 34.1 km cycling climb averaging 5.2% (+1818 m), rising from 1010 m to 2800 m in Tucson & the Sky Islands.
Arizona's hardest road climb by PJAMM's rating, and its state hill-climb championship for more than four decades: 5,689 feet of gain the race bills as the third highest of any one-day event in the United States. CCC-built, paved for 21.7 miles, ending at a locked gate below the observatory.




34.1 km · +1818 m · 5.2% avg · ~9.0% max · 1010 → 2800 m · 23 hairpins
Stats computed from OpenStreetMap and satellite elevation data — approximate.
Download GPX ↓Navigate to the foot ↗
Gradient by colour: ● <3% ● 3–6% ● 6–9% ● 9%+
Where it bites
Steepest 500 m: 8.6% (km 20.4–20.8).
| km | to | avg |
|---|---|---|
| 1 | 1016 m | 1.4% |
| 2 | 1049 m | 2.5% |
| 3 | 1094 m | 5.0% |
| 4 | 1115 m | 3.1% |
| 5 | 1205 m | 5.9% |
| 6 | 1261 m | 5.4% |
| 7 | 1319 m | 5.8% |
| 8 | 1379 m | 5.9% |
| 9 | 1461 m | 8.4% |
| 10 | 1540 m | 7.5% |
| 11 | 1597 m | 6.7% |
| 12 | 1685 m | 8.0% |
| 13 | 1763 m | 7.9% |
| 14 | 1830 m | 6.7% |
| 15 | 1877 m | 4.7% |
| 16 | 1946 m | 6.5% |
| 17 | 2013 m | 7.2% |
| 18 | 2081 m | 6.2% |
| 19 | 2134 m | 6.9% |
| 20 | 2197 m | 5.3% |
| 21 | 2269 m | 7.0% |
| 22 | 2329 m | 6.5% |
| 23 | 2399 m | 6.9% |
| 24 | 2477 m | 7.4% |
| 25 | 2547 m | 6.9% |
| 26 | 2593 m | 4.9% |
| 27 | 2635 m | 4.1% |
| 28 | 2687 m | 6.2% |
| 29 | 2698 m | 1.0% |
| 30 | 2718 m | 1.9% |
| 31 | 2729 m | 1.1% |
| 32 | 2762 m | 3.7% |
| 33 | 2784 m | 2.0% |
| 34 | 2794 m | 1.0% |
What it’s like to ride
The Swift Trail leaves the Gila Valley floor near 3,000 feet among cactus, yucca and mesquite, and holds a fairly continuous 4-5% for the first five and a half miles before stepping up to around 7.6% for the next four. From there the road starts folding back on itself, with two big hairpin sections near miles 10 and 14 and a series of five hairpins stacked together at Turkey Flat, the valley opening up below at every turn. The vegetation does the work of telling you how high you are, desert scrub giving way to oak grassland, then pinyon and juniper, then pine, spruce and fir near the top, and riders regularly see a 30-degree temperature swing between bottom and summit. Carry everything you need: there is nowhere on the climb to get food or water, the nearest shop is back down in Safford, and traffic is light enough that a car passes maybe every ten or fifteen minutes. The pavement ends at a parking area near 9,000 feet, where a locked gate and a graded dirt road carry on toward the Mount Graham International Observatory and Riggs Flat Lake. Much of the asphalt is rough with patches of loose gravel, so the descent asks for more care than the gradient suggests, and the road has hosted the Mt. Graham Hill Climb, Arizona's state championship hill climb, every year for more than four decades.
History
The Swift Trail was built during the Great Depression by the Civilian Conservation Corps, and takes its name from T. T. Swift, the first supervisor of the Coronado National Forest. Arizona adopted the route as SR 366 in 1960, at first 6.3 miles of gravel running southwest from what was then US 666, extended another 22 miles later that same year to the Columbine Ranger Station to open up the Coronado National Forest. The lower 21.7 miles are paved today, the remainder stays gravel, and part of the route carries the Swift Trail Parkway designation under Arizona's Parkways, Historic and Scenic Roads program. The road hosts the Mt. Graham Hill Climb, one of the longest running bicycle races in Arizona: it reached its 42nd edition in 2021 and doubles as the Arizona State Hill Climb Championship. The course starts on SR 366 across from the Federal Correctional Institution at Safford and runs west up the mountain to finish near Snow Flat Campground, an elevation change of 5,689 feet that the race bills as the third highest of any one day race in the United States, with riders choosing the full 20 mile event or a 10 mile version. PJAMM Cycling rates the ascent the hardest road bike climb in Arizona.
More climbs in Tucson & the Sky Islands
Common questions
- How long and steep is Mount Graham (Swift Trail, AZ-366)?
- Mount Graham (Swift Trail, AZ-366) is a 34.1 km cycling climb averaging 5.2% (+1818 m), rising from 1010 m to 2800 m in Tucson & the Sky Islands.
- Where is Mount Graham (Swift Trail, AZ-366) steepest?
- The steepest 500 m averages 8.6%, between km 20.4 and km 20.8 of the climb.
- How many hairpins does Mount Graham (Swift Trail, AZ-366) have?
- Mount Graham (Swift Trail, AZ-366) has 23 hairpin bends, counted from the road's map geometry (a hairpin here means at least 150 degrees of turning completed within 150 metres of road). Painted corner numbers on some climbs count gentler bends too, so the two figures can differ.