Monument Hill and Base & Meridian Wildlife Center
Right in the heart of Avondale lays a piece of Arizona’s geographic history. The initial survey point for the state of Arizona lies where the base line and principal meridian meet – right on a hill just east of Phoenix International Raceway.
The hill was constructed in 1851 by the US Boundary commission to draft a survey for the United States-Mexico Boundary under the 1848 Treaty of Guadalupe-Hidalgo. In 2002, it received status to be on the National Register of Historic Places.
Just below Monument Hill sits the Base & Meridian Wildlife Area. This area is approximately 198 areas and sits on the north bank of the Gila River. Visitors who come to this outdoor oasis gives a glimpse of Arizona wildlife, as the area is teeming with birds, mammals and fish, as well as a variety of vegetation like cottonwood, willow and mesquite trees.