The astronomers of Lowell Observatory perform most of their observations through the telescopes on Anderson Mesa. This large plateau about twelve miles southeast of Flagstaff provides skies much darker than those available on Mars Hill. With the 1961 addition of the Perkins 69 inch (soon to become the Perkins 72 inch), it became clear that a site was needed that would be more immune to the growing light pollution of Flagstaff. Anderson Mesa was a logical choice for several reasons. It is in the Coconino National Forest so it cannot be developed (hopefully); it is on the south edge of the Colorado Plateau at an altitude of 2200 m.; it is easily accessible via good roads from Flagstaff. So, in 1961, Anderson Mesa became Lowell's dark site. For those with an eye for detail, the Anderson Mesa site is at -111 deg. 32.2 min. east longitude and 35 deg. 05.8 min. latitude.
In 1970, funds from the Lowell endowment were used to construct a new 24 foot diameter dome on Anderson Mesa. This dome housed the A. Lawrence Lowell Astrograph, the 13 inch camera used to discover Pluto. The instrument was moved to Anderson Mesa because the bright lights of the growing city of Flagstaff had made the it ineffective in its original location. Between 1970 and 1992, the Astrograph was used initially by Dr. Henry Giclas for a proper motion survey of the stars. Later it was used by Dr. Ted Bowell to search for asteroids. Beginning in 1993, the dome has been undergoing rennovations to accept the LONEOS telescope. The astrograph has been moved back to its original site on Mars hill. The southern-most concrete pier has be modified to accept the LONEOS Schmidt. The lower level of the dome now has a warm room to house the astronomers, computers and other contol gear. It also has a vented equipment room which houses the camera refigerator and other equipment that produce large amounts of unwanted heat. Electrical and communications lines are being upgraded to handle increased demands.