The tallest mountain in Arizona is located atop the 5000’ Colorado Plateau. Mt Humphrey’s located in the San Francisco Peaks north of Flagstaff is 12,633’ above sea level. The most commonly used trail to the top starts at the base of the Arizona Snow Bowl Ski area at 9200’.
From the trailhead the trail starts across the cleared ski slope and into a crowded forest of aspen and pine. The predominate trees here are, Douglas and white fir, Englemann spruce, and ponderosa pine. There are many dead and downed trees in this first section and if when you stop to catch your breath you can hear them rubbing against one another high up in the canopy. The sounds can be creepy in this strange mixture of live and dead trees.
The view of the valley to to the west as you walked across the ski slope will have to serve for a while, because views of anything but trees and the rock-littered trail are rare in the first 4 miles of this trail as it winds through steep wooded slopes.
The trail itself is straightforward and nearly impossible to lose at this point. It is also not steep considering that it climbs 3000’ in about 5 miles. Here the trail makes long lazy switchbacks along the western slope of the San Francisco Peaks.
The San Francisco peaks are the result of an explosive volcanic history dating back at least 15 million years. The oldest volcanic rock on the mountains themselves date to about 2.8 million, with the last eruption that blew out the entire eastern side of the volcano having occurred around 200,000 years ago.
The San Francisco Peaks are part of a much larger volcanic field that begins near Seligman Arizona, to the west, which has the oldest volcanic fields of around 15 million years ago, to Sunset Crater to the east of Flagstaff, which erupted 1000 years ago. The age of the entire field trends from west to east, with the San Franciso Peaks being the most striking example.
The San Francisco Peaks lost their classic volcanic shape around 220,000 years ago when a Mt St Helens style sideways blast blew out the entire northeastern flank. The three peaks that remain on the west are the former edges of a caldera that has since exploded and been worn smooth by glaciation during the Pleistocene.
The three most prominent peaks remaining are (from S. to N.) Fremont, Agassiz and Humphrey’s Peak. Together they form a 3/4 circle around the blown out northeastern face of the volcano.
The trail, in spite of it’s fairly easy slope starts at 9200 feet and ends at 12,633. There is far less oxygen at this elevation than at sea level or even in the town of Flagstaff which lies at the feet of the San Francisco peaks at 7000’. Elevation causes physiological changes that can affect your hike. Starved muscles will cry out for the scant oxygen causing you to breath harder, your heartbeat will also rise. The air at elevation holds far less water and therefore expect to drink more to combat dehydration. Altitude sickness can happen to anyone regardless of other factors. Fitness, age and sex have no correlation with altitude sickness. Altitude sickness can occur at 8000’ and can include headache, nausea, feeling dizzy, loss of appetite and inability to sleep.
Near mile four the trail suddenly brings you to the treeless Agassiz saddle. To give you an idea of the elevations involved here, the saddle stands at 11,800’ . The trail Ts here with the trail to Mt Humphrey on your left and Weatherford Trail heading towards your right. The peak to your right is Agassiz. Take a moment to breathe and appreciate the expansive views that extend in both directions, down into the blown out Inner Basin and the volcanic fields extending out to Sunset Crater (noticeable for it’s bands of red and black cinders) and west across the high Colorado Plateau.
To your left rises the first of three increasingly disheartening false peaks that obscure your final destination. The trail from here becomes rugged and barren as you leave the last twisted bristlecone pines behind and arrive onto the low scrubby tundra. Lichen and small clumps of flowers provide a welcome splash of color against the dark volcanic rock.
Bring a light windbreaker for this section, which is exposed and chilly even in the summer. Watch the skies for storm clouds - this is not a place to be in a lightening storm. May and June provide the best options for escaping late afternoon summer storms.
The trail is harder to follow here, but you cannot get lost. There is minor scrambling and no exposed edges. The air is extremely thin here, so take your time, enjoy your surroundings, ad prepare for a very long mile.
The San Francisco Peaks were initially called Sierra Sinagua (no water) by Spanish Conquistadores who passed through en route to the Grand Canyon and their quest for gold. The name never stuck. In 1629 Franciscan Friars named the mountain range San Francisco after their patron saint St Francis Assisi.
The San Francisco Peaks are one of the sacred mountains of the Dine’ (Navajo). Called Dook’o'oosłííd,which means "the summit which never melts" or "the mountain which peak never thaws." It is the Mountain Adorned with Abalone Shell (There are variously 4,6 and 12 sacred mountains in the Navajo traditions). All of the sacred mountains are adorned with different sacred stone.
The peak itself, once you have arrived (via many curses laid at the heads of the three preceding false summits) offers spectacular views in all directions. To the north you can see the red rock walls of the North Rim of the Grand Canyon. To the east past Sunset Crater you will see the worn clay buttes of the Painted desert. South slightly obscured by Agassiz Peak is the town of Flagstaff (the white dome of NAU is clearly visible). To the west you can trace your trail back to the base of the ski run.
For a longer route from the east try the Weatherford Trail. It is far longer at twenty miles and has a larger elevation gain. Camping is permitted below thee tree one but not above.
For a detailed description of the Mt Humphreys Trail.