What it means
The Rim is where the Valley goes when it cannot take any more. The Mogollon Rim is the southern edge of the Colorado Plateau, a wall of pale cliffs that runs about 200 miles across central Arizona from near Sedona to the New Mexico line, and from the top of it the ponderosa forest stretches north for a hundred miles. Below it is Payson; above it, at 7,000 to 8,000 feet, are the lakes and cabin towns where Scottsdale spends its July weekends. Locals almost never say “Mogollon.” They say “the Rim,” “up on the Rim” or “Rim Country,” and mean the whole cool high country two hours north rather than any particular cliff.
The word carries a shibboleth. “Mogollon” is not pronounced the way it is spelled, and how you say it tells people how long you have been here. The day trips guide covers the drive; this page covers the word.
Where you’ll meet it
On the Beeline every summer Friday, in the traffic; in weather forecasts, where “Rim Country” gets its own line; in the summer resort playbook, as the escape hatch; on the 1990s and 2000s history pages, where the Dude and Rodeo-Chediski fires smoke the horizon; and in every conversation that begins with the first 100-degree day.
Where the word came from
The Rim is named for a Spanish colonial governor who never saw it. Don Juan Ignacio Flores Mogollón governed New Mexico from 1712 to 1715, and his surname went onto the Mogollon Mountains of southwestern New Mexico. From there it migrated west onto the great escarpment of Arizona and the plateau above it, by a route that no one has documented; the Sharlot Hall Museum’s historians say only that the Rim “may have been” named for him, and no primary source records who first applied the name or when. Archaeologist Emil Haury added a third use in the 1930s, naming the prehistoric Mogollon culture of the mountains, distinct from the desert Hohokam, after the New Mexico range.
The pronunciation came apart somewhere in the nineteenth century. In Spanish the double L is a Y sound and the name is roughly “mo-go-YOHN.” Anglo settlers flattened it, and the result, which the Sharlot Hall Museum renders “mug-ee-yown” and Payson renders “muggy-own,” is what Arizonans say today; Archaeology Southwest gives “mug-e-own” for the culture too. The spelled-out “mo-GOLL-on” is what newcomers say and what locals quietly file away. The two older names are simpler: the Tonto Rim, after the Tonto Apache country below it, which Zane Grey used in his Rim novels, and plain “the Rim,” which has won.
What the word came to mean in the Valley is a season. Payson, about 90 miles from Scottsdale up the Beeline, became the Valley’s cabin town once the highway was paved, and the Rim lakes above it, Woods Canyon, Willow Springs, Bear Canyon, became its campground. By the 1970s “going up to the Rim” was the Phoenix equivalent of going to the shore, and it still is.
What it is not
The Rim is not Flagstaff, which sits on the plateau 60 miles north of the edge and reads as its own place. It is not the Mogollon Mountains or the ghost town of Mogollon, both in New Mexico. And “Rim Country” is a tourism term for Payson and its neighbors, Pine, Strawberry, Christopher Creek, below the actual cliff; the Rim itself is the escarpment and the forest on top, inside the Tonto, Coconino and Apache-Sitgreaves national forests.
The fine print
The geology is a textbook case. The Rim marks the southern limit of the Colorado Plateau, where Kaibab Limestone and Coconino Sandstone, laid down in the Permian, stand as cliffs up to 2,000 feet above the country to the south, which sits at 4,000 to 5,000 feet. Interstate 17 cuts through it near Camp Verde; SR 260 climbs it east of Payson; Forest Road 300, the Rim Road, follows the edge and is the drive everyone should do once. Happy Jack, on top, gets 60 to 100 inches of snow a year, which is why Scottsdale children see their first snow here.
The Rim is also a border for living things. Rocky Mountain plants and animals reach their southern limit on the plateau; Sierra Madre species from Mexico reach their northern limit on the slopes below. The ponderosa forest across the top burns accordingly: the Dude Fire of June 1990 killed six firefighters below the Rim near Payson, and the Rodeo-Chediski Fire of June 2002 burned about 468,000 acres east along it, Arizona’s largest fire until 2011.
Two cautions on the name. The link from Governor Flores Mogollón to the Arizona Rim is conventional, not proven; every source hedges, and the first printed appearance of “Mogollon Rim” in Arizona is undated in the literature we could open. And the “right” pronunciation is a local convention rather than a rule: the Spanish is defensible, the Payson version is standard, and the only wrong answer is the one that rhymes with “Babylon.” For what the escape costs in gas and time, and whether to bother in monsoon season, see the best time to visit guide.