Grand Falls



In northeastern Arizona, east of Flagstaff and just off Leupp Road. Closest city or town: Leupp; Flagstaff. The falls are on the Navajo Reservation east on Leupp Road, at the eastern edge of the San Francisco Volcanic Fieldʼs 1,800 square miles (4,700 km^2) landscape, marking the southern boundary of the Colorado Plateau.


36 deg 11'28"N 111 deg 48'14"W (At Leupp: 35 deg 17'51"N 111 deg 0'20"W)

Kindly note: Unlike most of the other sample diaries, this diary's pictures did not preserve its cache of photos. Ergo, it's all informative verbiage from here to the end. Regrets!

Lava-based falls in the planed topography of a desert landscape. Ephemeral and dramatic flows during (mostly) the spring runoff, and to a lesser extent, the monsoonal season. A former molten magma flow that blocked a riverʼs course, creating a basaltic stair-stepped profile of lofty waterfalls. An aptly named Arizona natural wonder. For many people, an annual pilgrimage to see and hear the Little Colorado at its loudest (and muddiest).

Geology, waterfalls, lava and basaltic dams.

A thunderous display with wind-blown spray rising up from the base of the falls. Typically, the Little Colorado River denotes a smaller drainage flowing down from Arizonaʼs White Mountains near the border of New Mexico and the Mogollon Rim (pronounced “moog-ee-oyne”) sector along the southern edge of the Colorado Plateau. A desert landscape where magma once merged with water, then turned into steam. Thus a moving mass of lava, whose temperature ranged from 1,292 to 2,192 degrees Fahrenheit (700 to 1,200 degrees C). Eventually, the flow merged with the Little Colorado River (hereafter, “LC”). Geologists do not agree on exactly when the eruption occurred, though it may have been as recent as a few thousand years ago or the figure stretches back to tens of thousands of years. Likely, the eruption issued from the Merriam Crater (about 20 miles/ 32 km east of Flagstaff), although some geologists argue a smaller regional volcano may just as well have been the source. The suitably named Grand Falls is located close to the start of the Little Colorado River Gorge that funnels into the Grand Canyon at mile-60. This deep, narrow chasm was not originally incised by the LC, which is the only major tributary flowing into the Grand Canyon.

Guided Tour Essentials
The Little Colorado Riverʼs sole claim to fame relates to its dramatic display of waterfalls during the short-lived spring runoff. Otherwise, itʼs typically shallow draft and slow-moving tempo produces a minimal cubic feet per second (c.f.s.) rate-of-flow. Thus itʼs only when Mother Natureʼs adds volume to the river that it accelerates, and smooth water becomes roiled. Tracing its pathway down from the White Mountains, by the time it gets to the Painted Desert watershed, notably Holbrook, Joseph City, Winslow, Cameron and Leupp, to mention some metropolises it passes, the river vectors toward the sLittle Colorado River Gorge where the basaltic falls begin. From there, it courses through the sinuous corridor to a terminus inside the Grand Canyon. Although the LC is typically a muddy-brown tincture, once out of the gorge, and closer to the typical pea-green Colorado River, the brownish water turns a gorgeous turquoise color due to travertine deposits in that sector (i.e., a form of limestone deposited by mineral springs).

In view of the LCʼs typical shallow drainage, it often appears more like a stream than a river. With scant ponding here and there, including frequent mudbanks and patches of quicksand, sometimes there are stretches where its width is reduced to a slender tongue within the wide banks of its channel. Hence, a wet or dry sandy bottom with abundant riverine verdure, especially the ubiquitous tamarisk (from the family Tamaricaceae). In the shadowy gorge, for some months itʼs as though the river had lost its power and prematurely ended its run long before its intended terminus, at the Colorado River. Hence, a body of water with a distinct personality change compared to its ramped-up temperament during the spring runoff and monsoonal seasonal rate-of-flow.

More Guided Tour Essentials
The formation of the Grand Falls is directly linked to regional volcanic activity. A literal river of magma from nearby Merriam Crater (6,385 feet/1,946 m) southeast of Flagstaff (or some nearby volcanic outlet) that erupted and flowed for about 7 miles (11 km), eventually funneling into a nearly 200-foot-deep (60 m) fissure, marking a new upper sector of the gorge. The molten rock display continued as magma lapped up and over the canyon's opposite rim, then flowed downstream another 15 miles (24 km) before literally running out of steam and heat. This high volume flow of lava therefore dammed the LCʼs original course due to a thick basaltic barrier (i.e., where the magma initially entered the channel). As a consequence, the river was forced to alter its original course, thus making a wide horseshoe bend to the east. From there, it flowed around the margin of the lava flow. Over time, a new channel was carved. In the process, the LC excavated portions of the cooled and congealed lava foundation that filled its former channel.

The fairly recent spectacle of falls thus created by a magma flow is indeed a riveting and roaring display spilling over sedimentary steps in the Kaibab Limestone Formation that once was part of the north wall of the gorge. When its drainage is flooding, the spectacular cascade of the LC comes alive and readily earns its epithet: The Grand Falls of the Little Colorado River.

Basalt is lava-based and dark in color. Its formation contrasts nicely with the opposite rim of the Grand Falls, which is composed of horizontal layers of wan-colored limestone of the Kaibab Formation. The vicinity of the gorge is extinct volcano country (so far extinct), boasting some six hundred volcanoes in this sector of the San Francisco Volcanic Field. Craters range in age from around 6-million-years-old to less than one thousand years, approximating the Cenozoic Era's Miocene to Holocene epochs (respectively, 23 to 7.2 myr to some 10,000 or 12,000 years ago, and perhaps even younger). Sunset Craterʼs eruption some nine hundred years ago denotes the most recent activity. The largest volcano in the assembly is Humphreys Peak, at Flagstaff's northern perimeter. At 12,633 feet (3,850 m), Humphreys is the highest of six summits on this stratovolcano popularly known as the San Francisco Peaks.

LC Facts
Rising as two principle forks in Arizonaʼs White Mountains, the West Fork begins in a valley on the north flank of Mount Baldy at an elevation of nearly 10,000 feet (3,000 m) and the East Fork begins in this vicinity, eventually joining at the town of Greer. Thus the LC gets its main impetus at this locale, eventually meandering its way into the Painted Desert terrain. In this locale, itʼs destined to become little more than a shallow desert wash, with an average discharge around 450 c.f.s., though a minimum average of 150 c.f.s. is usual. The only exception is when the river is at flood stage. Then the c.f.s. can be something on the order of 120,000 c.f.s., whose raging floodwaters are ephemeral, at best.

Although itʼs not a lengthy river (i.e., 315 miles/507 km), the LC nevertheless drains a large area of about 26,5000 square miles (68,635 km2) in eastern Arizona and western New Mexico. By the time its drainage closes in on Cameron (Arizona), this usually nondescript river during the springtime and monsoonal season takes on a new personality. When its c.f.s. is extreme, the quiescent river temporarily changes its nature, thundering its own applause at the start of the gorge. That 185-foot (56 m) plunge makes the waterfall what it is: the Grand Falls of the Little Colorado River. From there, the river winds and sings its way into the deepening chasm, eventually reaching its terminus inside Marble Canyon, at the juncture with the Colorado River.

Hiking (with a geologic lesson along the way)
For the physically fit hiker, the best way to see and understand what happened here is to go on a hike. Once at the falls there is a crude trail of sorts to the west (in the downstream direction), which vectors along the rim of the canyon. Take care, because there are many confusing branches and false turns. Hence, it usually takes time to find the right path. (Note that itʼs not exactly the yellow brick road of OZ, even though countless hikers have blazed a fairly discernible pathway over time.) After about 100 yards (91 m), the trail becomes rocky and gradually descends over outcrops of basalt. Notice how there are no visible crystals in the lava. Their absence indicates the lava cooled quickly and crystals did not have time to form. Take time to examine the numerous tiny holes in the basalt. Known as vesicles, the myriad holes signify gas bubbles that were once trapped in molten lava. In some places, these telltale markings are elongate or lens-shaped. The reason is because the gas bubbles were stretched as the lava continued to move while its high-temperature flow cooled and solidified. Venturing deeper into the gorge, notice the fracture or joint patterns in the basalt foundation making up the dark right wall of the canyon. Look for columnar patterns, also called columnar joints. When lava cools, it shrinks or contracts, creating highly noticeable cracks in the process, thereby forming the observable joints in volcanic rock.

If the falls are flowing and matching the decibels of a rock concert, the view of the cascading water from below is spellbinding, perhaps even somewhat terrifying for some people. For those who are not intimidated by such a visceral sight and sound, keep going and get used to it. Notice how, on the right side of the falls, the ledges of the Kaibab Limestone end abruptly against the dark-colored basalt. Directly below the ramada on the left the rough hewn lava is also very thin, yet to the right it thickens rapidly along a steep boundary that cuts sharply down to the bottom of the canyon. What is the reason for this? The answer lies in the dramatic contact zone that represents the north wall of the OLD river canyon when the lava filled this sector. Eventually, the magma dammed the river. The massively thick plug of basalt to the right is also interesting. This particular lava stock is the actual remains from Merriam Crater (or a crater nearly like it) that completely filled this part of the gorge. The thin basalt cap just beneath the ramada also marks the place where molten lava lapped over the rim of the old chasm sector. After resting and listening to the white noise of the falls, it's time to head back up the trail and get used to the quiet again.

Recommended Reading:

Drive I-40 headed east from Flagstaff (14 miles/22 km), then take the Winona Exit 210. Drive 2 more miles (3.2 km) on the Townsend- Winona Road, then turn right on Leupp Road to the Grand Falls turnoffs. Another option is to drive 2 miles (3.2 km) past the Flagstaff Mall (eastern Flagstaff), then turn right at the traffic light onto the Townsend/Winona Road. Drive east 8.3 miles (13.3 km) and turn left onto the Leupp Road (Navajo reservation country). Follow Leupp Road for 15.3 miles (24.6 km) and turn left onto a wide dirt road (Navajo Road 70), which has a sign for “Grand Falls Bible Church” soon after the cattle guard (marking the boundary of the Navajo Reservation). The rounded cinder cone on the left is Merriam Crater, which is the probable source of the lava that initially created Grand Falls.

The rough road to Grand Falls is very dusty (also very muddy during the rainy season). Washboard bumps are ca-ca-ca-ommmon. The main route is also converged on by several other secondary roads. Ergo, pay attention! Stay on the largest and most heavily used road. Ergo, pay even closer attention to the odometer and drive for 8.6 miles (13.8 km), then turn left onto a smaller dirt road about 0.7 mile (1.1 km) past the junction of Navajo Road 6910 (which enters from the right). However, if you find yourself at the river, you have plainly missed the turn! What should happen next (if this scenario happens) is follow the rough road for about 0.5 mile (.8 km), then park near the rim of the canyon below the last ramada of the picnic area. The trail, which may or may not be marked, starts just downstream (west) about 100 yards (91 m) from the parking area. Because the falls are located on the Navajo Reservation, do not wander off main roads or do anything to violate their laws. If you run into trouble, call the Navajo police, because this turf is entirely their jurisdiction. Yah-ah-tey, as the Navajos say, and have a grand time visiting the Grand Falls of the Little Colorado!

Contact Information
Navajo Nation Tourism, P. O. Box 653, Window Rock AZ 86515. Phone: 928-800.8501. Fax and Email: non-listed. Another option is to contact the Navajo Nation, Leupp Chapter House, Leupp AZ 86035. Phone: 928-686.3227.

As always, your thoughtful commentaries are welcomed.

Happy Trails!