to the south by passing through Stein's Pass, Apache Pass and Nugent’s Pass, then down Tres Alamos Wash to the Lower Crossing of the San Pedro River below Tres Alamos. From there it linked up with Cooke's Wagon Road at a waterhole, near modern Mescal. 1855 to the 1880s: Dragoon Pass, Pacific Wagon Road, Doubtful Canyon Cutoff Dragoon Pass and the Pacific Wagon Road In 1856, a Railroad Survey Expedition modified the Tucson Cutoff route, passing south of Nugent's Pass using Dragoon Pass and the Middle Crossing or San Pedro Crossing of the river instead of the Lower Crossing below Los Alamos. In 1857 following the Gadsden Purchase, as part of the Pacific Wagon Road, a military road being built between El Paso and Fort Yuma, a wagon road was built from Mesilla westward to Cooke's Spring, saving the longer route via the San Diego Crossing. The Pacific Wagon Road then followed Cooke's Wagon Road and the Tucson Cutoff as far as the west side of the Apache Pass. There it made another shortcut across Sulphur Springs Valley to Dragoon Pass, and then down Dragoon Wash to the San Pedro River. The route then descended northward on the right bank of the river to the Middle Crossing of the San Pedro River. From this crossing the Pacific Wagon Road ran due west to link up again with Cooke's Wagon Road at Mescal Springs to continue on to Tucson, Arizona, then turned northward to the Pima Villages and Maricopa Wells where it turned westward along the Gila River following it to the ferries on the Colorado River across from Fort Yuma. The Pacific Wagon Road shortened the route still further for travelers. Doubtful Canyon Cutoff From 1859 to 1861, during the time of the Butterfield Overland Mail, the stages and other traffic ran over a shortcut between Ojo de Vaca and Apache Pass, over the Peloncillo Mountains through Doubtful Canyon. However following the destruction of stage stations and coaches and the killing of their keepers and drivers at the outbreak of war with the Apache in 1861, this route was abandoned. Favored ambush country, the shortcut was unwise to use unless the travelers were a strong detachment of soldiers or under military escort by one. Even so, in May 1864, California Volunteers fought a Skirmish in Doubtful Canyon with Apache that tried to ambush them there. Traffic returned to the Pacific