 The starting point was high on Cerro Grande, a 10,200-foot (3110-m) summit on the rim of the Valles Caldera not far north of New Mexico State Road 4, the main highway through Los Alamos County.Like many mountains in the Jemez, Cerro Grande was mainly covered with coniferous forest, composed largely of Ponderosa pine, Douglas fir, white fir, and aspen trees, with a characteristic rincon (meadow) on its southern slopes near the summit.This grassy area also represented the headwaters of Frijoles Creek ("Rito de los Frijoles"), which flows southeast into Frijoles Canyon and on to the Rio Grande, passing en route the main tourist areas at Bandelier.