The Dirty Lemmon

5 Star Route

Note: This is a 5 Star Route, meaning that it is a highly curated, premier riding route.

George Simpson of the Elevate KHS Pro Cycling team rode this route for us and gave it the approved 5 Star rating. For George, it was a bit under 7 hours of ride time. For mere mortals (like Captain ‘O’), this is a big, big endeavor! But … the payoffs are huge: (a) the accomplishment of a monster climb (4400 feet in 13 miles), (b) one of the longest and most scenic paved descents in the West, and (c) bragging rights with your riding friends.

Update!! Four women of Team Twenty24 did the entire route in March of 2121, including the dogleg to the very top. We have included some of their pictures and metrics. We encourage you to learn more about the Team and it’s work with women in sports by going to the Get Involved tab.

And if none of that captures your fancy, there is the San Pedro River Valley sector (miles 26 to 40) that is one of the most valuable riparian ecosystems in the Southwest[The Ribbon of Green] and has one of the highest concentrations of Clovis cultural artifacts in North America.[University of Arizona]

The Clovis culture is a prehistoric Paleoamerican culture, named for distinctive bone and ivory tools found at Blackwater Locality No. 1 near Clovis, New Mexico in the 1920s and 1930s. Clovis people are considered to be the ancestors of most of the indigenous peoples of the Americas.[Wikipedia]

Adventure / Gravel Route

Loop with dogleg: 114 miles / 12,000 ft gain
– Surface: ~ 50% gravel, 50% paved
eBike Friendly: Yes
– Location: Tucson, AZ
– Published: December 2019 (updated January 2021)

Terrain & Technical Difficulty Rating[what this means]

50% Remote & Rugged, 50% Paved & Fast

Reddington road and the Mt Lemmon Control road (the backside gravel climb) are rugged, rocky and sometimes rutted.

When we like to ride this ..

Fall and spring, when you have a bit more daylight and the temperatures are more moderate. We do not recommend this route in the winter as the Control Road can hold snow and ice. In the summertime, the route can be extremely hot, and water becomes a concern.

The Start

Agua Caliente Regional park. Flush toilets and water.
Lat / Long: 32.281464, -110.728947


Red = paved road
Brown = gravel / dirt road

Ride Details

Intense! More than 50% off-road…some of the most concentrated climbing I’ve seen, and what has to be one of the longest descents anywhere.

Ok, some quick details, this was a really dumb idea, and I wouldn’t recommend doing it alone, but I would recommend doing it if you can find someone who appreciates suffering and is a little dumb as well.

Start as early as possible!…possibly at dawn, to check out the sunrise. I started some time after 8 am and got back to my car in the dark. If I had any issues or mechanicals, I would have been in trouble because of the remoteness of most of this route. You’re basically in a valley (the San Pedro River Valley) that requires ~ 7500 feet of climbing to escape from….or backtracking 40 miles. I would consider warmer clothes and an emergency bivy if I did it again. (Note, I did this ride in mid-January).

Also, bring lights.

My ride.

This route starts from the parking lot of Agua Caliente and, in a short time, heads up and over Reddington Pass. This area seems to be one of the gravel destinations for people riding from Tucson. It’s a switchbacky climb with some great views. This isn’t the smooth and relaxing gravel of the midwest or northeast; it’s chunky. I was running 2.2” tires.

After Reddington, it gets really flat for a long while, the San Pedro Valley River sector. The dirt turns to rough pavement [~ mile 41], and there was always a headwind. This would be a good spot to have a partner for some drafting.

The San Pedro River valley is the most significant migratory flyway remaining in the Southwest. Nearly 400 species of birds spend part of their life-cycle along the San Pedro, and during peak migration, between 1 and 4 million birds are found there. Part of the Madrean Sky Island Archipelago, the entire valley’s exceptional richness provides a well-watered, verdant corridor for birds running from Sonora, Mexico to the Rincon / Catalina Mountains. [San Pedro River Valley]

Looking back at the San Pedro River Valley.

There’s a resupply around mile 48 in the town of San Manuel. It’s a convenience store, so you can get some liquids and a snack…but for some reason, they don’t sell Combos. There was a non-operational food truck outside, so there is potential for a culinary surprise if you pass by on the right day!

After San Manual, the pavement continues west towards the backside of Mt Lemmon. This is the kind of climb that slowly grinds its way up, but it almost looks flat or even downhill at points. Maybe your eyes are fooled, but your legs certainly notice. These are some of the worst climbs.

I should mention that around mile 59 or so, there is a zip line place where the pavement turns to dirt that was advertising burgers, so that’s a potential stop as well. Though, I’m not sure I’d want to eat a burger right before the next leg of this route. This is also the boundary to the Coronado National Forest and the Santa Catalina Mountains.

The Santa Catalina Mountains are a rugged range with steep slopes and deep canyons. The vegetation is strikingly diverse, with mixed conifer forests at the highest elevations and on north-facing slopes. Ponderosa pines predominate on many high elevation south-facing slopes. The higher elevation deep canyons, particularly those with running water, support lush hardwood forests of bigtooth maple, aspen, New Mexico locust, Arizona walnut, Gambel oak, and velvet ash. [US Forest Service]

Once you’re on the dirt (the Mt Lemmon Control Road), it’s mostly up, except when it’s not, and there are some dicey downs in this area. After the rolling gravel, you get pretty close to Mt Lemmon, and it really starts to go up, 5500’ pretty much straight up [~ mile 70]. This just might be the most absurd climb I’ve done. It’s really windy, loose in points, chunky, and I got treated to some snow and ice. It’s relentless. It’s all rideable, but it still takes a long time. It feels like it took me 4 hours to go 15 miles.

Mt Lemmon Control Road

At the top, you pop out on General Hitchcock Highway, also known as the popular paved road that heads up Mt Lemmon from the south. There are a lot of pro-roadies that train on this in the winter…and it does seem like it would be a fun climb and descent if it were a warm day. It was not a warm day. It was 30 up there, and I only had a sun shirt and minimalist wind shell…also, it was getting pretty dark, and I had some lights.

If you have the energy and daylight, make it to the official top by taking a right at mile 80 and finishing out the last bit of the climb: roughly 3.5 miles and 1300 feet of gain. Dusk was descending on me fast, so I gave this a pass.

Catalina Sky Survey (CSS), on Mt. Lemmon, is a project to discover comets and asteroids and to search for near-Earth objects (NEOs). More specifically, CSS is to search for any potentially hazardous asteroids that may pose a threat of impact. [Wikipedia]

Catalina Sky Survey
(Photo Credit: Wikimedia)

The descent is about 7000 feet in 29 miles, so it takes a while. Also, there are people who like to race their cars up and down the highway, and there were rocks and snow in the road at points. It’s really steep and there is some incredible exposure in places. I’m sure I would have loved it if the circumstances were different. But I just clung to the bars, stopping occasionally to shake the numbness out and warm them up. The whole way down I was really questioning the decision to even start this ride. But I survived and am in a warm place, so I’m appreciative of the whole experience. This is type 2 fun…which is great, but that’s sometimes better to share with someone else.

The Descent!
Food / Water

At ~ mile 47, there the Salt & Pepper convenience store in San Manuel where water and snacks can be had.

At ~ mile 78, in the resort town of Summerhaven there is a pizza shop and cookie shop. This requires about a 0.5 mile detour with a bit of elevation loss.

Route Notes

The route is suited for big tires. 40 mm is pretty much the minimum you want. 650b’s at 50 mm or 29’ers at 2.1″ would be even better!

We recommend a red blinky light and a front facing white light for the descent from Mt Lemmon.

On the backside gravel climb of Mt Lemmon, if the gate is closed do not proceed. The gate is closed each year at ~ December 1 to allow for animal migration and for maintenance. Contact the Santa Catalina Ranger District of the Coronado National Forest for gate status.

Ride Options

If you skip the short dogleg to the Catalina Sky Survey station [at ~ mile 80], the route is then 107 miles and 10,700 feet of gain.

Ridden and Reviewed by …

JayR / Guest Contributor

“A flat-bar mountain biker who’s developed a taste for gravel after frequently sampling it in order to link up bits of singletrack. Now occasionally enjoys a straight-up gravel ride with a twist of the bars. Also, lives in an Airstream with his dog.” Follow Jay on Instagram!

Get Involved!

The first group to ride this route in full since we have published it as a route guide were four women from the Twenty24 professional cycling team. They were Natalie Francov, Jen Luebke, Shayne Powless, and Charlotte Backus. The Twenty24 Cycling Team has had a tremendously positive influence on women, both young and the not so young, in cycling, body image, and health. If you’re looking for a way to give back to cycling, we encourage you to take a strong look at the Twenty24 Team.

TWENTY24 Professional Cycling is operated under Tam Cycling Inc. in accordance with Section 501(c)(3) of the US Internal Revenue Code.

This corporation’s purpose shall be to educate and foster national and international amateur and professional athletic competition, especially among women. The TAM CYCLING CLUB, in its commitment to empowering female athletes for a better tomorrow, will work in partnership with the entire community to assure equity and provide services, opportunities, and leadership necessary to establish and maintain safe, quality cycling programs. The coaches, trainers, and members of the club believe in the equal worth and dignity of all cyclists. As the community organization for female cyclist in the United States, the Tam Cycling Club is responsible for establishing a climate that:

  • Provides female athletes who desire to compete, the coaching and camaraderie that will help them achieve competitive and non-competitive cycling goals in a safe and enjoyable manner.
  • Develops in them an awareness of what it is to be an athlete that is both gracious and respectful to their community.
  • Creates an environment in which they may discover new friendships and find lasting role models.
  • Guides athletes towards learning new skills and disciplines and spreads the foundations of bike racing in the USA, especially among women.
  • Promotes the value of cycling to our community as a mode of transportation and as a lifelong sport.
  • Supports the equal treatment of women in not only the cycling community but in all women’s sport.


Revision History

  • March 2021 / Updated with pictures and ride metrics for Team Twenty24 ride. Placed route guide into new tab format. Added Team Twenty24 to the Get Involved tab.
  • February 2021 / Posted as a 5 Star route after work with JayR.
  • March 2020 / Original Post as a Development Route.

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