Always bring plenty of water, sunscreen, a hat, and especially a camera. During the summer, lightening from thunderstorms is a hazard on exposed ridges. Be aware of flash flooding in the summer, even when no rain is falling.
Park along Maple Drive about 500 feet north of the intersection of Maple Drive and Sumac Lane in Ponderosa Estates (Los Alamos). There is no trailhead signage at this location, so look carefully for the start of the trail adjacent to a house heading west along the south side of the canyon at the sharp bend in the road.
The Perimeter Trail
shortly intersects several other access trails. Always bear right heading in a westerly direction along the side of the canyon in this section. The trail gradually rises and is separated from nearby houses by a low ridgeline so that runners enjoy a measure of solitude. However, this narrow singletrack is also a very popular with mountain bikers, so listen for oncoming traffic and be prepared to step off the trail for safety.
In about 1.3 miles, the trail intersects the Mitchell Trail #69
for a few yards. Several wooden signs help guide the runner over a low ridge and back onto the Perimeter Trail
which then traverses the Western Perimeter. Proceed over a low ridge and continue straight when the Perimeter Trail
heads to the right. Skirt below a water tank and make a crossing of a dry stream channel. The trail continues up the dry canyon bottom. Look for rock cairns and logs on the north side of the trail marking a side trail that climbs steeply to the Los Alamos Natural Arch.
The very popular Natural Arch Trail
is 0.2 miles and an ascent of 300 feet. The rock arch forms a great picture frame for views of the Sangre de Cristo Mountains and the townsite. It also provides much needed shade in the hot summer months. After visiting the arch, proceed east down the old Mitchell trail 0.5 miles until it intersects the Perimeter trail. Continue heading east on the Perimeter Trail
to the trailhead in about 1.3 miles to complete the loop.