McElmo Phase refers to a period in the late 11th and early 12th centuries, when drastic changes in ceramics and masonry techniques in Chaco Canyon appeared, archeologists initially suggested that the McElmo influence was brought to Chaco Canyon by immigrants from which site located in Montezuma County, Colorado, it protects some of the best preserved Ancestral Puebloan archaeological sites in the United States?
Mesa Verde National Park
Title: McElmo Phase
Passage: McElmo Phase refers to a period in the late 11th and early 12th centuries, when drastic changes in ceramics and masonry techniques in Chaco Canyon appeared.  During this period the Ancestral Puebloans living in the canyon started using painted black-on-white pottery versus their standard grey ware, and the masonry and layout of great houses built during the McElmo phase, which was the last major construction era in the canyon, differ significantly from those built during the early parts of the Bonito Phase (850 to 1140), which overlaps with the McElmo Phase.  Archeologists initially suggested that the McElmo influence was brought to Chaco Canyon by immigrants from Mesa Verde, but subsequent research suggests that the developments were of local origin.  Archeologist R. Gwinn Vivian notes, "The jury is still out on this question, a problem that poses intriguing possibilities for future work."
Title: East Community
Passage: East Community is an Ancestral Puebloan great house community and archeological site located 12 miles east of Pueblo Bonito, at the eastern end of Chaco Culture National Historical Park, New Mexico.  Archeological evidence uncovered during the 1980s suggests the site was occupied by both Chacoans and Mesa Verdeans.  Eighty-two structures have been identified in the area, including a great house that contains twenty-five rooms and several small house sites.  At least one kiva has been uncovered there, but no great kivas.  A partial road segment is visible there, but archeologists are unsure of it connects with a longer segment thought to originate near Pueblo Pintado.  The great house at East Community was constructed in the 10th century, with significant additions completed during the 11th century.  The associated small house sites were occupied by Chacoans from 875 to 1300, and thirty-nine of them by Mesa Verdeans, from 1175 to 1300.  Archeologist Thomas Windes believes the site was linked to Chaco Canyon through a system of signaling stations atop the area's mesas.
Title: Mesa Verde National Park
Passage: Mesa Verde National Park is a National Park and World Heritage Site located in Montezuma County, Colorado.  It protects some of the best preserved Ancestral Puebloan archaeological sites in the United States.
McElmo Phase Mesa Verde National Park