What is South Mountain Park and Preserve?
South Mountain is the long dark wall that closes off the Valley to the south, and almost all of it is a Phoenix city park: more than 16,000 acres across three small ranges, the Ma Ha Tauk, the Gila and the Guadalupe, with over 100 miles of trail for hiking, mountain biking and horses. The city opened it in 1924 and has been adding to it since; by acreage it is the largest municipal park in the United States, and from the inside it does not feel municipal at all. Hohokam petroglyphs sit beside the Mormon and National trails, old stone ranger houses line the wash below Pima Canyon, and the National Trail runs the length of the range for roughly 14 miles with the city invisible for stretches at a time.
The part most visitors see is Summit Road, which climbs from the Central Avenue entrance to Dobbins Lookout at 2,330 feet, a stone shelter built by the CCC in the 1930s with the whole metro area spread out below. On Silent Sundays the road is closed to cars, all day on the fourth Sunday and until 10 a.m. the rest, and it fills with cyclists. The South Mountain Visitor Center at 10409 S. Central Ave., renovated and renamed from the Environmental Education Center in 2024, is open Thursday through Sunday from 9 to 3, and the paved, half-mile Judith Tunell Accessible Trail loops out from it with benches and fountains.
What you get is a free, enormous desert park with a drive-up view and trailheads on every side. What you do not get is solitude at the popular ends on a winter weekend, shade anywhere, or any forgiveness from the rock between May and September.
How to do South Mountain right
Nothing to pay, one thing to book. Entry, parking and trails are free. Ramadas require a special activity request, 72 hours to six months ahead, and are open to all after 6 p.m. Gates and lots open at 5 a.m. and close at 7 p.m.; the trails stay open until 11, but your car will be locked in.
Get there for the lookout. Take Loop 202 west from Scottsdale Road (or Loop 101 south to the 202), then I-10 west to Baseline Road, west to Central Avenue, and south to the park gate at 10919 S. Central Ave.: about 30 minutes without traffic. Summit Road climbs about five miles from the gate to Dobbins Lookout. Arrive 40 minutes before sunset, walk the shelter loop while the grid lights up, and be out before the gate at 7.
Get there for the trails. For the east side, Loop 202 to I-10 south, exit at Guadalupe Road, west to 48th Street, then follow the signs into Pima Canyon (4500 E. Pima Canyon Rd., about 25 minutes). The Mormon Trailhead on 24th Street is the short steep way to the same Hidden Valley loop; Javelina Canyon off 46th Street is the quiet one. The Desert Foothills Trailhead in Ahwatukee (14251 S. Desert Foothills Pkwy.) is the south-side entry to Telegraph Pass, about 35 minutes, and it is the lot that still has space when the others do not.
Pick the season, and the hour. October through April, this is an any-hour park. From May to September it is first light only: south-facing slopes, black rock, no shade, and the city rescues more than 200 people a year from its mountain parks. The summer rules are not optional here, and the city closes trails outright on excessive heat warning days.
Water. At the visitor center, the main-entrance picnic areas and the larger trailheads; nothing on the trails. The National Trail is long, dry and exposed; carry for the whole day.
Share the road. Summit Road is narrow, winding and shared with cyclists and pedestrians at all hours. Drive it like a trail. On a fourth Sunday, bring the road bike instead; the car-free climb to the lookout is the best paved ride in the city.
Dogs. On leash, and banned on all Phoenix trails once the temperature hits 100 degrees, which rules out most daylight from late May through September.
Skip it if you want granite, washes and a trailhead with a ranger: the McDowell Sonoran Preserve is the Scottsdale equivalent, closer to home and cooler by a few degrees. South Mountain is the one to bring visitors to, because the view from Dobbins is the whole Valley at once; see where it sits among the best hikes near Scottsdale.
The mountain Phoenix bought for $17,000
The range was the Salt River Mountains on the Army maps, and before that it had O’odham names. The Akimel O’odham and Piipaash, whose Gila River Indian Community begins at the park’s southern fence, have lived around it, in the city’s own acknowledgment, since time immemorial, and the Hohokam before them irrigated the valley on both sides and cut petroglyphs into the rock of all three ranges; the panels along the Mormon and National trails are among the densest in the Valley. A stone inscription in the park attributed to the Franciscan Marcos de Niza in the 1500s is, most historians now think, an early 20th-century forgery.
The park began as a land deal. In 1924, a committee of Phoenix boosters, J.C. Dobbins of the city planning commission among them, persuaded the federal government, with Senator Carl Hayden’s help, to sell the city 13,000 acres of the range for $17,000, about $300,000 in today’s money. The federal government had considered making the mountains a national park; Phoenix got them as a city park instead, briefly called Phoenix Mountain Park, and renamed Dobbins Road and the lookout for the man who pushed the purchase through.
The park as you drive it was built by the New Deal. From 1933 to 1940 two Civilian Conservation Corps camps worked the mountain, and their crews built the summit road, the first trail system, the ramadas and stone ranger houses, and the stone shelter at Dobbins Lookout that is still the best free view in the city. They hauled rock from North Mountain for the masonry. One project was never finished: a 500-foot tunnel meant to link Telegraph Pass to a road on the south side, which would have made the range a drive-through rather than a wall. A 1994 Arizona State University study by Michael I. Smith catalogued the CCC’s work, and most of it is still in use.
The city kept buying. Bond programs in the 1970s and early 1980s added the western and southern foothills and pushed the park past 16,000 acres, the figure that makes it the largest municipal park in the country. It also made the range a barrier to a growing metro area, and in the 2000s the state proposed to drive the Loop 202 South Mountain Freeway through its western end. The Gila River Indian Community, whose members voted against the route in a 2012 referendum, and the Sierra Club sued; the Ninth Circuit rejected the claims in December 2017, and the freeway opened on December 21, 2019, cutting through the preserve’s western foothills and taking a slice of the park with it.
The park turned 100 in 2024. Phoenix marked the centennial by renovating the Environmental Education Center and reopening it as the South Mountain Visitor Center, and by counting: about 850,000 visitors a year, over 100 miles of trail, and a free gate. The next changes are smaller and ongoing, more trail closures on heat days and more rescues on the National Trail, which is what happens when a desert mountain sits inside a city of five million.
Why it matters
South Mountain is the proof that a city can own a mountain range and mostly leave it alone. Phoenix bought it before anyone wanted it, let the CCC build the bones, kept adding land through the decades when it could have sold it for subdivisions, and lost only a freeway’s width in a century. It is also the Valley’s reminder of whose land it was: the O’odham community on the far side of the fence never consented to the freeway and said so in court. For a Scottsdale visitor it is simpler. It is half an hour away, free, and has the one view that shows the entire Valley at once. Drive up for sunset with the out-of-town parents, hike it from Pima Canyon in January, and stay off it between May and September unless you are on the trail at dawn.