Pajarito Canyon/Nail Trail Re-Re-Visited

In the mid-1990s, mountain bike riders began regular excursions up rough route that climbed the Pajarito fault south of Camp May Road.  It was steep, rocky, and hugely challenging.  I was younger then and remember cleaning the uphill once—out of 50 tries. The fun and hard work were rewarded with a long, twisting descent in Pajarito Canyon. The four-mile loop was unofficially adopted by the newly formed Tuff Riders Mountain Bike Club and we worked on improvements for National Trails Day in 1999.

Shortly after, we started having a run of more-than-expected flat tires along the uphill stretch. That’s when someone discovered a 50-foot stretch of trail laced with roofing nails amid the pine needles. The rumor was that a permanent camper in the woods up there hated the sound of bikes rattling by and tried to discourage wheels on the trail. Although the rumor wasn’t confirmed, the name Nail Trail stuck.

After the Cerro Grande fire raced over Pajarito Canyon, the trail up the drainage was the second major project we tackled. (The Forest Service only allowed us to work on the mesa top Quemazon Trail, out of any potential flood zone, until the end of the monsoons.) For many of us, it was our first major experience with the effects of post-fire flooding. Above the Dungeon climbing area, the stream crossings were blown out, and in spots the channel was entrenched a couple feet, putting the trail on the edge of a steep gully. We built two reroutes and a four-foot high rock wall that still holds up the trail about 300 feet up the canyon from the climbing area.

The Nail Trail after Cerro Grande

Up the canyon near the Nail Trail, aspens had encroached into the tread. Any vegetation seemed sacred and we were loathe to cut them back. But naturalist Dorothy Hoard, approaching her 70^th birthday but still helping cut trail, rightly told us there would be plenty of aspens sprouting in the burned area and not to worry. Wow, was she right!

Below the narrows and the climbing area, the canyon bottom trail was completely gone and covered with boulders. We asked if we could move the trail to contour around the hills to enter the canyon at the narrows, coming in from the south. That segment was our first chance to build an entirely new trail that was a bit more bicycle friendly and erosion resistant.

If fire wasn’t enough, changing rainfall patterns in the 2000s altered the Pajarito Canyon/Nail Trail loop. Several rain events in 2006 and 2007 were classified as “100-year storms.” The effects of intense runoff from the rocky slopes were noticeable on the challenging uphill section of the Nail Trail. The old road funneled water, and the increased volume and velocity scoured the trail to bedrock. What had been a route where you could pick a line to make a slow, steady climb was transformed into a series of rock ledges with tire-trapping wedges. Over the years, the Nail Trail became mostly a downhill journey for technical riders only.

As the landscape recovered from the Cerro Grande flames, the loop became one of my favorite hikes. In spring and summer, the north-facing slopes of the canyon shimmered with lime-green aspens. The canyon bottom always whispered with moving water. And I could count on spotting 60 or more species of flowers in bloom on a mid-summer’s day, including endangered day lilies. If the Nail Trail climb was hot, the shady descent through the canyon was always refreshing.

Wood lily in Pajarito Canyon

The Las Conchas fire back burn, ignited to push the flames around the west edge of town, ran pretty hot up the canyon. It never jumped into the crowns of the old ponderosa pines growing on the slopes, but it singed their trunks and scorched their needles. The area was classified as moderate burn, but most of the conifers and aspens in the canyon were killed by the heat. The result was a completely different trail re-building challenge for round two.

My first look at the canyon and Nail Trail mesa in September 2011 was a bit deceiving. The landscape along the Nail Trail wasn’t much different than before the fire: burned trees, some shrubs. What I didn’t realize was missing was the thick stands of young aspens, the fallen logs from Cerro Grande-killed trees, and grass clumps. In the canyon, only the lower quarter mile was black, the rest was tawny red with singed needles still on the trees. I figured most of the recovery would be easy.

The Nail Trail after Las Conchas

Well, those denuded slopes took a lot of water over the summers of 2001 and 2012. A couple of “100-year storms” and maybe a “500-year storm.” With nothing, not even fallen snags, to slow any runoff, the slopes would shed sheets of water during rain events. By the time we were permitted to work in the canyon in June 2012, the hill slopes were gullied, the trail cut by channels, and tons of gravel dumped on the trail.

A lot of the work just above the narrows was cutting back brush from a year of disuse, but the work got harder the further up we went. New retaining walls were built next to walls constructed in 2000. The trail bench was re-cut and literally tons of gravel washed from upslope were pushed off the tread, raising choking clouds of dust. We built rock ramps through new drainages, cut out fallen trees, and even suited up in long sleeves and pulled out 8-foot tall stinging nettles. By the beginning of July, after 4 weeks of evening and weekend work sessions, I was feeling pretty good—the trail was back, mostly. Only the first quarter mile needed a complete rebuilding.

Volunteers tackle the Pajarito Canyon Trail, June 2012

All of this work couldn’t have been accomplished without unwavering support from Lynn Bjorklund of the Santa Fe National Forest recreation staff. A Los Alamos native and avid trail user (I’ve seen her using local trails on foot, bike, and skis), Lynn made certain that all the forest service requirements were met so that when a crew of volunteers showed up they could get to work. Lynn leveraged a few dollars of trail repair funds into many more dollars through grants, cost share agreements, and contracts. So when I suggested we rebuild the lower part of Pajarito Canyon out of the floodplain, she got the approvals necessary. And I had a group of young girl scouts who wanted to help repair a trail.

Everything came together for the evening of July 11, especially the storm clouds. I arrived at the trailhead to the sound of thunder, not unusual at 4:45 PM in summer. Fifteen minutes later, I was sheltered in my truck as the clouds dumped torrents along the Jemez foothills. When the girls arrived, I chased them home and was about to follow when curiosity took hold—I wonder what the canyon looks like.

I was soaked in 10 seconds. Sheet flow poured down the slopes, and gullies were gouged out as I watched. The little side drainage next to the trailhead flowed about four-feet deep, preventing access to the canyon. To the south I could hear a roar that sounded like a train, so I headed that way, but again the path was blocked by raging water. At about 5:20, the rain eased a bit, and I found a way to reach Starmer’s Gulch. Since I had been there earlier in the day, I had a pretty good estimate that the wall of water headed downhill was six feet deep. I retreated when I was overwhelmed by the feeling that the entire mountain was eroding away under my feet.

Sheet flow in Pajarito Canyon, July 11, 2012

At the truck, I noticed that the bucket in the truck bed had about 3 inches of water inside. “I wonder what that translates into for inches of rain?” Duh, 3 inches.

Recording rain gauges on the hills above me confirmed that about 2.5 inches had fallen in roughly 20 minutes. No trail, much less one inside a burned area, can survive that much water in such a brief time.

Several times during the summer I was asked why I was pushing so much trail work be accomplished in such a short time. Having been through the post-fire process once, I knew the important thing was to stabilize the trails—rough them in, find where the water wants to go and encourage it to do so, and get people to pound them in a bit—before the rains come.

The next day I went out to survey the damage. Water cut a little deeper through the channels we created for it, and a lot of new gravel had been dumped on the tread. Cleaning the gravel off wasn’t difficult, but we’d have to go over every foot of trail a second time to clean up the mess.

Young trailbuilders from the Y Environmental Service Corps on the Pajarito Canyon reroute

And we did. Clean up was a hell of a lot easier than it was stabilize the trail earlier in the year, and it went a lot faster. Yes, we had built some sweet channel crossings that were washed to the Rio Grande, but that was the only real damage (we’ll rebuild those in a year or two when we can expect less water flow).

Current Conditions: Despite the repair work, the Pajarito Canyon/Nail Trail loop didn’t get much use over the summer. This allowed the resident population of New Mexico locust, with its razor-sharp inch-long thorns, to encroach into the trail. Several of us spent fall weekends digging the locusts out, and once they were gone, trail use, always heavier in these parts in the fall, picked up.

The new route to the Dungeon climbing area was complete by the almost rain-soaked girls scouts, the Family YMCA’s Y Environmental Service Corps and Youth Conservation Corps, and a handful of volunteers. That section of the trail is better than ever. A mysterious bridge builder spanned the five-foot gully of the main channel with a log-and-wood bridge that make the easy passage complete (a bridge of the channel cut into the southern route to the narrow is built in the same style, same builder?).

Above the climbing area, the trail is very steep and continues to be rutted by each storm. From that point up canyon, the trail is wide, open, thorn-free, a bit gravelly, but a great walk and a fun bike ride.

The Pajarito Canyon Trail is in pretty good shape for spring excursions

The old road section of the Nail Trail remains a problem. The road was used as a fireline during the suppression action and the bulldozer created low berms on the downhill side of the trail. This traps water on the trail and has led to increasing erosion. This section is more technical than before the fire for bikes, and a lot rougher on foot. Passable by both, but not quite as much fun.  

The lower section, the part that drew us to the trail in the 90s, remains tough. We a little work it could become the new Quemazon Trail, a challenging but clean ascent and descent that would attract a few more users.