The Navajo meridian, established in 1869, is one of the two principal meridians for Arizona, the other being the Gila and Salt River meridian. Its initial point was stated as latitude 35° 45' north, longitude 108° 32' 45" west from Greenwich, but has been revised as (35°44′56″N108°31′59″W) The Navajo meridian and baseline were used to set townships and ranges in a special survey for the original Navajo Reservation, and was set at the eastern boundary of that reservation.