Photo by  Ivgotit

Photo by Ivgotit

With a permanent settlement near the summit, as well as an observatory, Mount Lemmon is a hospitable peak to climb. And after a long ascent, you’ll be happy to spend a little more time relaxing in the cool air on the flat summit, before descending back to the desert heat.

Name: Mount Lemmon
Height: 2,795 m (9,171 ft)
Location: In the Santa Catalina Mountains near Tucson, Arizona, USA.
First Climbed: unknown. First ascent by a woman (white) was in 1881 by S Lemmon.
Climb Time: Half to a whole day
Best Time to Climb: Year-round


From uphill marathons to gentle drives to the forested summit, Mount Lemmon is an attractive landmark seen for miles around; an ultra-prominent sky island in a desert landscape. 

Jump to Climbing and Hiking Guide 

The high point of the triangular mass that is the Santa Catalina Mountains, Mount Lemmon (2,795 m/ 9,171 ft) is an accessible mountain offering a range of possible challenges. 


Mount Lemmon is named after the 19th Century botanist, Sara Plummer Lemmon. She is described as ‘a vibrant, curious woman who was challenged by the beauty of the mountain’s plant life and harshness of its precipices.’ After moving to the warmth of California for her health, she had a significant impact on the botanical explorations in the south-western states.

More poignantly for us, she is credited with being the first white woman to ascend the mountain (1881), a fact that no doubt contributed to the naming of the peak in. She also designated the golden poppy in 1903, which became the state flower of California, and has a number of flowers named after her. It’s unclear whether any of these grow on the mountain named after her though!

The local indigenous people are the Apache or Abachi peoples. Resident across Arizona, New Mexico and Texas, the Apaches clashed violently with white settlers, a quality made famous (or infamous) in numerous films and books of the early and mid-20th Century. This was the reason for putting a military presence on this mountain summit from the late 19th Century. 

The name Apache means ‘our enemies’ in Zuni, the language of the Pueblo Indians of New Mexico, suggesting this clash with the settlers wasn’t an isolated incident.

At the start of the 20th Century, Mount Lemmon became a major copper mining centre, with some minor gold prospectors also trying their luck. Today, a number of former mines can be seen around the mountain

The most famous, though as yet unfound, mine lies somewhere within the slopes of the Santa Catalina Mountains. It is behind a legendary door, the Iron Door Mine, and is said to contain the hidden gold mined and then buried by Jesuit priests ordered back to Spain in the late 18th Century. 

The Iron Mine Door is said to be one of the most eagerly hunted lost mines in the US, so keep an eye for it when you go for you adventure up the slopes!



Natural Geography.

Mount Lemmon is the high point of the Santa Catalina Mountains, a triangular groupings for mountains lying north of the town of Tucson. The elevation ranges from the top of Mount Lemmon to the lower reaches of Sabine Canyon, still 830 m (2,724 ft) above sea level.

The range is known for its steep rock cliffs and the desert vegetation that covers the foothills and canyon floors. From above, it appears like a single triangular mass, while from the surrounding area it looks domed. Both of these points make it unlike the typically sharp-crested ridges of other mountain ranges in south-eastern Arizona.

The range is a single massive block formed miles underground millions of years ago. Once at the surface, flash flooding, landslides and rockfalls have sculpted a varied and exciting mountain landscape of small and large rock forms. 

In the red rock, striated formations of Gneiss and Schist, up to 1.64 billion years-old, can be observed. These are the upper reaches of the bedrock that is the foundation to the whole range.

Nearby to Mount Lemmon stand smaller peaks, that are often classed as part of the Catalina Foothills. Yet Green Mountain (2,791 m/ 9,157 ft), Mount Bigelow (2,603 m/ 8,540 ft) and some 18 other peaks stand above 1,800 m (5,900 ft) and are mountains in their own right.

Mount Wrightson is the only peak in the Tucson area that reaches higher than Mount Lemmon, standing at 2,881 m (9,452 ft). It is situated to the south of Tucson, a couple of hours drive from Mount Lemmon, which is north of the town. 

In terms of Arizona state as a whole, Mount Lemmon is only the 38th highest peak, a list topped by Humphreys Peak (3,850 m/ 12,633 ft) in Coconino County.

Human Geography.

As with Pikes Peak (4,302 m/ 14,115 ft) in Colorado, Mount Lemmon has a road from its base to its summit; in fact, it has two!

The Catalina Highway is a 43 km (26.5 mile) paved road, built in 1933. It begins in Tucson away to the south of the mountain. It then winds through the canyons along the south-east flanks of Mount Lemmon, passing Summerhaven a little before reaching the true summit.

It is also known as the General Hitchcock Highway (the official name), the Mount Lemmon Highway and the Sky Island Scenic Byway. This final name refers to the name given to mountains whose ecosystem radically differs to the surrounding lowlands. In this case, the sky islands are forested peaks rising out of barren desert.

The second driveable route climbs unpaved up the north side of the peak. It begins in the small town of Oracle and pre-dates the main highway. It is most popular with 4x4 drivers wanting a little more adventure in their terrain! 

On reaching the summit, a real American mountain rarity is revealed. Mount Lemmon has a permanent community living on its summit—and they’re human too!

Established in the 1870s as a military base, Summerhaven now hosts 40 permanent residents (according to the 2010 census). It’s population blooms along with the wildflowers, with the few small shops and restaurants opening to serve the summer peak season arrival of tourists.

A round half a kilometre from the mountaintop stands another former military facility, the Mount Lemmon observatory. This takes advantage of the peak’s elevation to stare skywards. It is run, in part, by the local state university, and is a prominent education centre. It is also part of the significant Catalina Sky Survey, which as mapped 39,274 minor planets to date (September 2015).

In the baking heat of an Arizona summer, a motivation to get to the summit is the temperature change. Typically, Mount Lemmon’s summit is 20-30 degrees cooler (Fahrenheit) than at the base. Although in recent years, it seems the mountain is also heating up…



This sky island receives its name because of the flora that marks it out amongst its neighbouring peaks. All but barren lower down, Mount Lemmon reveals its foliage on the way up its slopes, welcoming summiteers to the top through a covering of pines.

This means that the mountain has two distinct vegetation zones. Lower down, the flora are desert-adapted cacti, grassland and shrubs. Higher up, pine, oak and fir forests take over. Meanwhile, in the sheltered canyons, well-fed by mountain streams, a woodland also thrives.

The saguaro cactus is a common feature in the desert areas. Growing to extraordinary heights, these plants retain water behind their thick and spiky exteriors. They are often surrounded by low lying shrubs, which appear like temporarily replenished tumbleweeds!

After rain, there is often a predominance of fungi growing out from between rocks as the forest thickens. This forest begins in oak and pine, while towards the summit there are more firs and ponderosa pines. 

The diversity of plant life is also notable, with species such as indian paintbrush, elderberry bushes and woolly mullen—an excellent substitute for toilet paper, should you need it!


Looking like something shrunken out of a horror movie, though actually harmless to humans, the camel spider lurks around small pools. Visitors to campsites are advised to keep an eye out, though the shock of their appearance really is the extent of their risk to us.

However, less harmless are multiple species of rattlesnake found around the peak, including the tiger and Arizona black. Bark scorpions and gila monsters are also worth keeping away from. The latter lives up to its name, with orange and black scales a pre-warning to its venomous bite. Steer well clear of all of these if you can, and ask local rangers/staff for advice on what to do should you encounter one.

But aside from those, the peaks boasts lots of more friendly fauna! An ubiquitous resident across the mountains in the southern and western states, the bighorn sheep is also found here. They’re impressive, backward curving horns and excellent balance make them a popular sight for trekkers and tourists alike.

White-tailed deer, black bears, bobcats, foxes and squirrels also inhabit the slopes, and the forested areas in particular. These are also common to the mountains of the south-west and west coast of the US.

Up above, the circling, soaring flight of the peregrine falcon is always a pleasure to witness. Up in the high-elevation forest, keep an ear out for the Arizona woodpecker, or a flash of bright blue that is the Steller’s jay. There are also two breeds of the small songbirds, tanagers; the western tanager is the more colourful of the two, with a red head and bright yellow underbelly.


Free and Sport Climbing.

Mount Lemmon is known to offer some of the best climbing in Arizona, with some 1,500 climbing routes on the mountain. There are crags located between 750 m and 2,750 m (2,500-9,000 ft) and the climbing temperatures are comfortable year-round. Challenges range from routes rated at 5.6 to those up at 5.13 (translated as a span from hard to almost impossible!)

Many climbing areas are located near to the highway. These include Windy Point and Prison Camp, which perhaps give their own impressions of what a climber will arrive to!

However, among the diversity of options, there are some dangers to still be aware of. 

Loose rock, dramatic swings of temperature and afternoon storms as well as old equipment left on the mountain all pose potential hazards to a safe climb. Some of the fauna are also less than accommodating (see above).

Flash floods, whose destructive power carved the shape of these peaks, are also a considerable and very real risk. If in doubt, avoid canyon areas and listen to local advice. While this may be an often climbed and popular mountain, it shouldn’t be climbed without decent preparation and due diligence.

While a lot of the climbing routes are available all year-round, be aware that there are some closures in the first half of the year. This is to protect areas of nesting/rearing for peregrine falcons and bighorn sheep. 

Hiking to the summit

In terms of arriving to the summit, there are a number of routes available for hikers. Trails and paths criss-cross the flanks of the mountain, although obviously the fastest and easiest route is straight up the Catalina Highway on some wheels!

Most of the trails, in typical US organised fashion, are simply numbered. One of the more popular trails is Mount Lemmon Trail No 5, which climbs directly up the south-west flank. Many other trails join this one or the highway within a couple of kilometres of the summit.

Similar in scale to an ascent of Mount Whitney (4,421m/ 14,505ft), though without the difficulties of thinning air, an ascent of this mountain is a significant undertaking. While not a technical challenge it is a physical one, so be well prepared for a long strenuous day reaching your reward of the summit. 

A good option for a hike to the summit, and one not taken as often as Mount Lemmon Trail No 5 and some others, is called the Sutherland trail. 

The Sutherland Trail is 18.5 km (11.6 miles) from trailhead to summit. The trailhead is in a car park on the north boundary of Catalina State Park, along Forest Road 643.

Begin by heading up this road under powerlines for a few kilometres until you reach a sign for Sutherland Trail No 56. Continue to head along this undulating path for around 5 km (3 miles) before the trail turns right suddenly and the real uphill trek begins. 

Now on Trail No 6, the trail has a tendency to appear and disappear, so make sure you consult your map and use natural landmarks regularly for guidance. This trail will take you up what appears to be an ever-growing, immense mountain; more of an illusion that a true reflection on your progress!

Eventually, you meet the Samaniego Ridge Trail No 7, and following this, you begin the final ascent. Gaining the Mount Lemmon Trail No 5, the summit is less than 2 km (1.25 miles) away. Around 500 m (1,640 ft) from the summit, you’ll pass the observatory. You have the choice to follow the road from here, or stay on the trail which loops around top the mountaintop. 


As the most frequented area of the Coronado National Forest, the Santa Catalina Recreation Area is littered with enticing trailheads, campgrounds and picnic areas. Day hikes and multi-day hikes criss cross the whole area, with a full list of options found here.

An alternative list of hikes near Mount Lemmon can be read here.

And for the more long distance challengers out there, the recently completed Arizona trail crosses from the border with Mexico in the south across the length of the state. This takes intrepid adventurers on a journey across deserts and sky islands, totalling around 1,300 km (800 miles)

For those wanting a shorter challenge, why not try the Mount Lemmon Marathon! 

First run in 2010, it races from the desert floor to Summerhaven on the mountain’s summit. It is, unsurprisingly, uphill all the way, and athletes gain over 1,800 m (5,900 ft) during the 42.2 km (26.2 miles). 

Its constant ascending nature has won it many accolades—if you’d call them that! It is known as one of the most difficult marathons in the world, as well as America’s only uphill long-distance race.

This is also the path of one of the ‘toughest, hardest and most difficult climbs’ on a bicycle, yet it this review also raves about it being the best mountains to ride up in Arizona.

Mount Lemmon Ski Valley is the southernmost ski location in the contiguous US. With 21 runs and the intriguing slogan ‘ski the lemmon’ (cue large snow-capped lemon as their logo), it is a rare winter attraction found this far south.