UPDATE: A detour route has been marked out (see below).
On Monday February 28, the Los Alamos County Department of Public Utilities began a construction project on the Pueblo Canyon Road at the low-water crossing just east of the the old Bayo Wastewater Treatment Plant (see map below). The road at the crossing will be closed to all public use from February 28 to around mid-June. Construction will take place along the floodplain.
The closure affects trail users coming down the Bayo Canyon and Pueblo Canyon trails and those heading west along the access road that begins at the highway yard at the New Mexico Highway 4/502 interchange.
A trail detour route has been marked that stays outside the construction zone. The detour permits trail users heading west along the access road to skirt around the work area and it serves as a way to connect the Bayo and Pueblo Canyon trails.
Watch for trail detour signs posted along the roads near where the construction zone begins. The routes are marked with orange flagging tied to trees and shrubs. The route isn't very fancy, but it has been located to avoid overhanging brush. The surface is rough, rocky and not maintained. There is a crossing of the outflow from the wastewater treatment plant that requires a long step or a short jump. The route won't appeal to mountain bikers, but it does keep the trail network in the canyon open for use.