Camp May Saddle to State Road 4 Pass.  Red = rim; purple = public road; green = existing route; magenta = recommended.

Access:  The road to the Pajarito Mountain Ski Area is paved from State Road 501 in Los Alamos.  Paved parking is readily available at the ski lodge in summer but tight during the ski hill season.  A dirt road climbs uphill to Camp May from the parking lot.  It is closed when snow-covered.

Valles Caldera East Rim

Camp May to State Road 4

Introduction: This set of reports of the rim of the Valles Caldera is divided into linear sections.  Most are anchored at each end by public vehicular access points.  This section of rim extends between paved parking at the Pajarito Mountain Ski Area/Camp May above Los Alamos and at State Road 4.  The Valles Caldera National Preserve, (VCNP) is closed to public access along the rim between Pajarito Mountain and Cerro Grande.  Its section is fenced and posted. Cerro Grande to State Road 4 in Bandelier National Monument is open for day use only.

Description: The Sierra de los Valles is composed of thick volcanic flows that formed the bulk of the Jemez Mountains prior to the eruptions that created the Valles Caldera.  The distinctive profile of the sierra is due to thick, pasty lava that piled into rounded domes.  Pajarito Mountain, at 10,441 feet is the midpoint of the Sierra; Cerro Grande, at 10,199 feet, is the dome that anchors the southern end of the Sierra de los Valles.  Between the two peaks is Valle Pass at 9,500 feet.

Camp May is a county park located uphill from the Pajarito Mountain Ski Area parking lot.  From the SW turn of the Camp May loop, a steep dirt road climbs to the rim.  This is a fire road and closed to unauthorized motorized use, however, hikers can climb to the saddle on the rim.

Unfortunately, the boundary between Ski Club property and the VCNP is fenced; current VCNP policies prohibit public access beyond the fence.  The fence extends along the saddle and the face of the slope.  Looking over the fence, one can’t see into the caldera, but it really doesn’t matter; a dense forest blocks views into the Valle Grande.  Even so, it is a nice climb with fine views to the east across the Rio Grande Valley to the Sangre de Cristo Mountains.

The Ski Club allows public access.  The boundary fence runs up the rim to the mountain top.  An informal trail along the fence leads up to one of the ski runs, appropriately called Rim Run.  Walking up (or down) ski runs is hard, but high on Rim Run the views into the Valles Caldera become truly spectacular.  At this time, the Pajarito Mountain Ski Club offers off-season lift rides monthly, a nice way to get up and down the north side of the mountain.

The view from Rim Run, showing Valle de los Posos, Valle Toledo, and the north rim of the Valles Caldera.  The east rim is along the tree line at left, extending up the ridge at upper right.  Camp May Saddle is the low point beyond the bottom of the run.

The VCNP restricts access to the western slopes of the rim.  On the back (southwest) side of Pajarito Mountain, the boundary fence descends straight down the mountain.    It is steep and very rocky—hiking the fence line is brutal.  During the 2000 Cerro Grande Fire, firefighters put in firebreaks along the rim between the summits of Pajarito Mountain and Cerro Grande.  The firebreak on the south slope of Pajarito Mountain is a wretched thing.  It goes straight down the steep, rocky mountain side and is treacherous for hiking.  However, a trail could be made quite acceptable with a few switchbacks.  The view on the VCNP side of the fence into the Valle Grande is the finest on the east rim even though the forest is encroaching into the grassland.  The pass at the head of Cañon de Valle is on the VCNP and closed to public access.  In reality, the best one can do here along the rim is climb to the top of Pajarito Mountain and look over the fence.

The VCNP kindly granted me a permit to investigate the east rim of the caldera.  We found an interesting trail, now mostly a game trail, that contoured around the west face of Pajarito Mountain over to the Camp May saddle.  It was marked with bicycle reflectors.  Now mostly game trails, the route travels through dense forest with no views, but it does cut off the rocky climb to the top of Pajarito Mountain, which also has dense forest and few views.

Along the Reflector Trail.                                The Valle Grande from Pajarito Mountain.

An abandoned road crosses the rim at Valle Pass.  It is one of the earliest routes, dating from the 1700s, used to drive stock from the Rio Grande Valley to summer pasture in the grasslands of the caldera.  The pass is closed to public access; the VCNP boundary crosses the road approximately a half-mile east of the pass.  Below the boundary, the Forest Service maintains the old road as a trail.  A route down the VCNP southwest face of Pajarito Mountain would make a good local hiking loop down to Valle Pass and then down Cañon de Valle to State Route 501.  The principal problem is that the VCNP does not allow dogs while the Forest Service does.  Walking with dogs is a popular, and increasingly restricted, recreational activity with Los Alamos area hikers.

The old road in Cañon de Valle is a nice hike          Aspen writing in Cañon de Valle.

There is no trail from Valle Pass up the rim to the summit of Cerro Grande.  However, during the 2000 Cerro Grande Fire, firefighters put in a so-called hand line directly along the rim.  It makes quite a pleasant trail.  The slope is heavily wooded, but the firefighters took out deadwood and the lower branches of the conifers to create a cleared fire line 20 feet or so wide.  They did not remove the canopy, so the area is shaded under the trees the entire way.  Parts are steep, but a trail could easily be contoured a bit to alleviate some steepness.  There are no views along this slope, but we found it to be a pleasant walk

At the summit of Cerro Grande, there is a small pile of rocks at the bench mark.  This is the beginning of public access.  From the summit of Cerro Grande, a little trail descends straight down the steep grassland to a high saddle, then down to a logging road in the upper north drainage of Frijoles Canyon, then over the shoulder of the hill to the Cerro Grande Trailhead on State Road 4.  On the south face of Cerro Grande is a typical Jemez Mountain high altitude meadow, called a Thurber fescue grasslands after the principal grass.  The views from this grassland into the caldera are restricted by the dense surrounding forest, but views to the south across the mesas of the southern Jemez Mountains and on to the Sandias above Albuquerque are truly wonderful.

The trail up Cerro Grande.                  View of the southern Jemez Mountains.  Rim at right;
Sandia Mountain at left under clouds.

When it opened its Cerro Unit in 2005, Bandelier National Monument established the Cerro Grande Trailhead at the paved parking area on State Road 4 just east of its junction with Forest Road 289 and marked the route up Cerro Grande.  It rapidly became one of the most popular walks in the monument.  The rim itself is on the slopes north of this trail.  A trail along the actual rim is feasible enough, but the area is heavily wooded and does not provide any advantages over the Park Service trail.  In addition, the actual rim descends to the pass on State Road 4. A continuation on the rim to the west up the slope of Scooter Peak is not practical.  The slope is dreadful: steep, with large boulders and piles of deadfall strewn about.  Even the fence line is difficult to follow.  Ken Kutac found a much better route west, more easily accessed from the Cerro Grande Trailhead.

Dorothy Hoard   September 2007