What is the Arizona Trail at Kelvin?
The Arizona National Scenic Trail runs 800 miles from Mexico to Utah, and the point where it was declared finished is here, on a ridge above the Gila River south of the Ray Mine, marked with a golden spike set in concrete on December 16, 2011. At the Kelvin-Riverside Bridge, where the Florence-Kelvin Highway crosses the river between the hamlets of Kelvin and Riverside, Passage 15 (Tortilla Mountains) arrives from the south and Passage 16 (Gila River Canyons) leaves northbound: 25 miles of singletrack that follows the river downstream through a gorge of saguaros, cottonwoods and dark rock, then climbs away through The Spine, Walnut Canyon and the Rincon to the Tonto National Forest boundary below Picketpost Mountain. The BLM manages the passage and calls it one of the driest on the whole trail, the river notwithstanding.
The day hike is simpler. From the lot at the end of Centurion Road, the trail drops to the river, crosses the Copper Basin Railway tracks, climbs two long switchbacks to a rocky ridge at 2,160 feet with the golden spike and a view north to the Ray Mine terraces, then descends into mesquite bottomland to a spur that leads to an old railroad bridge among the cottonwoods: about 6.1 miles round trip, moderate, with elevations between about 1,777 and 2,160 feet, and in a wet March one of the best wildflower walks in the state.
What you get is a winter river walk with saguaros on one side and cottonwoods on the other, free, open to hikers, horses and bikes, and nearly deserted. What you do not get is a toilet, a tap, shade on the climb or any reason to be here between mid-April and October.
How to hike Kelvin right
Pay nothing, sign the register. There is no fee and no permit for individual use. The passage crosses State Trust land, where trail users need no permit as long as they stay on or near the trail. Dispersed camping is allowed on the BLM land with a 14-day limit; the dirt lots have no posted hours.
Get there. US 60 east through Apache Junction to Superior, then SR 177 south about 15 miles to the Florence-Kelvin Highway at the railroad crossing (milepost 152). Turn right (south), drive 1.2 miles through Kelvin toward the bridge, and just before it turn right on Centurion Road for half a mile of dirt to the BLM trailhead. If it is full, the big lot at Riverside Road and the highway is across from the trail, and the Florence-Kelvin Trailhead is about 1.5 miles farther west. Parking at the bridge itself has been tight since the new bridge opened in 2018. Figure 100 minutes from Old Town, all paved but the last half mile. Weekends in March bring a dozen cars; the rest of the year you will be alone.
Find the trail. From the Centurion Road lot, backtrack 50 yards to the steel gate with the AZT logo and climb. The spur to the railroad bridge is on the left as the trail bottoms out in the mesquite, and the bridge is the turnaround. The ridge with the golden spike, about 2.3 miles in, is the lunch spot; the spike sits low to the ground and is easy to miss. Watch for a crested saguaro on the descent. Allow three to four hours.
Pick the season. November through early April. The canyon is below 2,200 feet, and the summer rules apply from mid-April on. The first two weeks of March after a wet winter bring poppies, lupine and bluedicks, the best wildflower display within two hours of Scottsdale on a real trail, with the cottonwoods just leafing out.
Water. None at the trailheads except a public spigot at the ADOT maintenance yard near the bridge. The Gila is murky, controlled by releases from San Carlos Dam and has tested positive for E. coli because of cattle along the banks; filter and treat, or carry it all. Do not try to ford the river at Cochran farther downstream when it is up.
Health. The Arizona Trail Association has posted norovirus advisories for the Kearny and Superior passages. Wash with soap and water, not sanitizer, and keep catholes far from the river, per Leave No Trace.
Bikes, horses and dogs. The passage is open to all three. Bikes may not enter the White Canyon Wilderness, whose boundary the trail grazes farther north. Dogs are allowed on BLM passages; pack out waste.
Skip it if you want a beach rather than a bridge: the Gila River Recreation Area at Winkelman is about 15 miles upstream. For flowers with a parking lot and a café, Boyce Thompson Arboretum is on the way home at Superior. The drive in on SR 177 passes the Ray Mine’s terraces, which is a fair reminder of what the river is up against.
A stage stop, a copper mill and the trail’s last spike
Kelvin started on the other bank. In 1877 a post office and stage station called Riverside opened on the south side of the Gila, a stop on the road that carried freight and passengers between Florence and the silver and copper camps around Globe. This was Western Apache country, and the road ran within a few days’ ride of the San Carlos Reservation. In November 1889 the stage climbing the Kelvin Grade north of the river carried nine Apache prisoners bound for Yuma; some of them overpowered and killed Sheriff Glenn Reynolds and deputy William Holmes, and one of them, the Apache Kid, was never caught.
Copper made the north bank. Ray Copper Mines Ltd., organized with British money in 1899, built a mill on the river, and the settlement around it took the name Kelvin in 1900. A 5.5-mile narrow-gauge railroad finished that April brought ore down from Ray. The railroad company later laid out Ray Junction just north of the crossing, and the line along the river is still there: the tracks the trail crosses belong to the Copper Basin Railway, which has hauled Ray ore to the smelter at Hayden since ASARCO bought the mine from Kennecott in 1986. The mine itself finished converting to an open pit in 1955, and Kennecott built Kearny in the late 1950s to house the families whose towns the pit swallowed.
The bridge came in 1917. Pinal County paid $43,995 out of a bond issue for a multi-span concrete Luten arch, one of only two multi-span Luten arches the state’s 1988 bridge survey found; it went on the National Register of Historic Places in 1988. When SR 177 was built, the bridge became a local crossing, and when the county finished its replacement in 2018, the old arches were left in place for walkers, riders and cyclists. That is where Passage 16 starts.
The trail is the newest layer. Dale Shewalter, a Flagstaff teacher, walked a route from Mexico to Utah in 1985 and spent years lobbying land agencies to make it official; the Arizona Trail Association incorporated in 1994, and Congress made it a National Scenic Trail on March 30, 2009. The Gila River Canyons were among the last pieces to be built, and on December 16, 2011 a small group gathered on the ridge above the river to set the golden spike. Shewalter had died in January 2010; his initials are pressed into the concrete. (Some accounts, including Arizona Highways, describe the last mile as finished in spring 2012; the dedication date on the spike is December 2011.)
Why it matters
Kelvin is a cross-section of how central Arizona was made: an Apache homeland, a stage road, a British copper mill, a railroad that still runs, a county bridge that outlived its job, and then, a century later, a footpath stitched across all of it by volunteers. The Arizona Trail is mostly experienced in pieces, and this is the piece with the most history per mile and the lowest elevation on the whole route. It is also the best place near the Valley to see the Gila as a river rather than a dry bed. For a Scottsdale visitor, the verdict is narrow but firm: a free, quiet, six-mile winter hike, best in early March, that you should not attempt once the canyon starts holding heat. Pair it with Picketpost or the arboretum and make a day of US 60.