The Petrified Forest National Park near Holbrook is adding 4,265 acres thanks to contributions from The Conservation Fund and the National Parks Conservation Association.
National Park Service officials say the land, which includes rare dinosaur fossils, was purchased by The Conservation Fund along with money from NPCA in January 2013.
The service says it used the federal Land and Water Conservation Fund to acquire the property.
Formerly known as the McCauley Ranch, the land sits east of the historic remains of Puerco Pueblo and connects parcels already protected within the park.
Officials say the additional land also contains numerous fossil-producing sites where this past summer researchers unearthed a well-preserved dinosaur skull.
Copyright 2013 Associated Press. All rights reserved.