THE SAN FRANCISCO VOLCANIC FIELD

Peaceful today, this 3,000-square-mile area of volcanic peaks, cinder cones, and lava flows presents some impressive landscapes and geology. The majestic San Francisco Peaks, highest of all Arizona mountains, soar 5,000 feet above the surrounding plateau. Eruptions beginning between 1.4 million and 400,000 years ago created this giant stratovolcano, which may have stood 16,000 feet. The center later collapsed, perhaps in a violent Mount St. Helens-style blast, forming a huge caldera, now known as the Inner Basin. During three Pleistocene ice ages, glaciers carved deep valleys on its slopes. Hundreds of cinder cones, of which Sunset Crater is the youngest, surround the Peaks. There's no reason to assume the San Francisco Volcanic Field is finished, either. The area has experienced volcanic activity, with periods of calm, during its long history. The first volcanoes in the field burst forth about six million years ago near present-day Williams. Later volcanoes sprung up progressively eastward, spreading 50 miles past Flagstaff to the Little Colorado River Valley, where the next eruption is likely to occur. On average, eruptions have occurred every 10,000 years, so we're not "due" for another for a while, as the last one was less than 1,000 years ago. Altogether, the field has more than 600 volcanoes.
    Tribes of northern Arizona regard the San Francisco Peaks as a sacred place. The Hopi believe that the Peaks are the winter home of their kachina spirits and the source of clouds that bring rain for crops. The Peaks also occupy a prominent place in Navajo legends and ceremonies, representing one of the cardinal directions.
    In 1984, the federal government set aside 18,963 acres of this venerable volcano for the Kachina Peaks Wilderness, selecting the name because of the importance of the site to the Hopi people. The Forest Service maintains a network of trails in the wilderness, and most of the volcanoes make good day-hike destinations. Cyclists may not ride here, even on the former roads, because of the wilderness designation. Foresters at the Flagstaff Ranger District (5075 N. Hwy. 89, Flagstaff, AZ 86004, 928/526-0866) offer maps and hiking information for this region. The book Flagstaff Hikes by Richard and Sherry Mangum lists many possibilities in the San Francisco Peaks area.

SUNSET CRATER VOLCANO NATIONAL MONUMENT

Sunset Crater, a beautiful black cinder cone tinged with yellows and oranges, rises 1,000 feet above jagged lava flows about 15 miles northeast of Flagstaff. Although more than 700 years have passed since the last eruptions, the landscape still presents a lunar-like appearance, with trees and plants struggling to grow.
    Eruptions beginning in A.D. 1064 or 1065 sent indigenous people fleeing for safety. By 1110 activity had subsided enough to allow them to settle in the Wupatki Basin, 20 miles northeast of Sunset Crater. You can visit the remains of their communities and see a museum in Wupatki National Monument, reached via the Loop Road, one of the prettiest scenic drives in Arizona. Geologists continue working out the history of Sunset Crater. Some studies place the eruptions within a short period between 1040 and 1100; others suggest that lava flows and smaller ash eruptions continued from Sunset Crater possibly as late as 1280.
    In the late 1920s, some Hollywood filmmakers thought Sunset Crater would make a great movie set. They planned to use dynamite to simulate an avalanche, but local citizens put a stop to their plans. Sunset Crater became a national monument in 1930. Before rangers prohibited climbing on Sunset Crater in 1973, hikers wore a deep gash in the soft cinder slopes. Most of the damage has been repaired, though you can still see faint scars. No off-trail hiking is permitted in the monument to protect both the landscape and the visitors.
    The road and trails stay open all day; an admission fee of $3 per person age 17 and up also includes entry to Wupatki National Monument. You can reach the monument's visitor center by driving north 12 miles from the Flagstaff Mall on US 89, then turning east two miles at the sign. This very scenic drive, known as the Loop Road, continues past Sunset Crater, drops down to pinyon-juniper country with views of the Painted Desert, crosses Wupatki National Monument, and then rejoins US 89 26 miles north of Flagstaff; the drive is 35 miles one way and takes about an hour without stops.
    You can experience the history of Sunset Crater at the visitor center (928/526-0502, www.nps.gov/sucr, 9 a.m.–5 p.m. daily, extended in summer, closed Dec. 25th). Video clips of recent eruptions elsewhere illustrate the fury that must have occurred here. An interactive computer program recreates Sunset Crater's birth and growth. Mineral and lava specimens include some with corn casts—apparent offerings by local tribespeople during the eruption. Seismographs track your footsteps (great fun for the kids) and report on activity nearby and around the world.

Lenox Crater (elev. 7,240 feet) provides the opportunity to climb a cinder cone with a crater. It's a short, steep ascent of 280 feet, requiring 30–45 minutes for the one-mile roundtrip to the rim and back. From the visitor center, drive about 1.3 miles east to the first pullout on the left.
    The self-guided Lava Flow Trail, which begins 1.5 miles east of the visitor center, loops across the Bonito Lava Flow at the base of Sunset Crater; allow 30–60 minutes for the one-mile walk, less for the paved quarter-mile inner loop that's wheelchair accessible. A trail leaflet, available at the start of the trail and at the visitor center, explains geologic features and ecology. You'll see a miniature volcano, lava bubbles, squeeze-ups, and lava tubes that seem to have cooled only yesterday.
    Cinder Hills Overlook offers a high vantage point on the northeast side of Sunset Crater, about five miles east of the visitor center. You'll see volcanoes in every direction and colors of the Painted Desert to the north. The overlook is just south of the Loop Road near the east edge of the monument.
    Painted Desert Vista is a bit lower, between Sunset Crater Volcano and Wupatki National Monuments, but still has fine views. Ponderosa pines mix with pinyon pines and juniper here. Picnic tables and a restroom are provided, but no water. You'll also find picnic tables near the visitor center and at the Lava Flow Trail.

Bonito Campground
In the ponderosa pines near the lava flow for which it's named, this national forest campground (928/527-1474 campground, 928/526-0866 Flagstaff Ranger District) lies across the road from the monument's visitor center. Sites at the 6,900-foot elevation offer drinking water, flush toilets, grills, and fire rings mid-April–mid-Oct. for $15 1st vehicle, $6 2nd vehicle, and $5 day use (10 a.m.–4 p.m.). There's usually room. Interpretive programs run on weekend evenings in summer. Groups can reserve areas at nearby O'Leary Group Campground (877/444-6777, www.recreation.gov).
    Dispersed camping is allowed in other areas of the national forest such as along Forest Roads 420, 552, and 418 west of US 89; Forest Road 776 (can be dusty from ATVs) south of Sunset Crater; and Forest Road 150 (hot in summer) south of the road through Wupatki. Visitor center staff can make suggestions and sell you the Coconino Forest map.

O'Leary Peak
Weather permitting, the summit of this 8,916-foot lava-dome volcano provides outstanding views into Sunset Crater. From the turnoff a quarter-mile west of the Sunset Crater visitor center, turn north 0.3 mile on Forest Road 545A, signed "O'Leary Group Campground" to the trailhead. Follow the former road on foot or by mountain bike five miles one way to the fire lookout tower at the top. The summit provides the best view of the colors of Sunset Crater and the Painted Desert beyond in late afternoon; the San Francisco Peaks look their best in the morning. No camping is allowed on O'Leary.

On to Wupatki National Monument