This map illustrates a critical aspect of the Mexican Boundary Survey (following the Treaty of Guadeloupe Hidalgo) with the determination of an agreed upon point (the middle of the Rio Gila where it enters the Colorado) to anchor the boundary line in the east. Shows the villages of Captain Pasqual, Capt. Anastasio, and Captain Anton in the vicinity of Yuma. Also shows the Old Emigrant Route and General Kearney's Route. Locates a rope crossing, the emigrant crossing and the lower crossing east of Santiago. An important and historical map that is finely engraved with good detail along the rivers.

References: Wheat (TMW) #653.

Condition: B

Issued folding, now pressed and backed with archival tissue. Some scattered foxing, else very good.