  The Cherenkov Telescope Array (CTA) is a major ground-based observatory
proposed for gamma-ray astronomy. CTA is envisioned to consist of two large
arrays of atmospheric Cherenkov telescopes for the study of sources of
high-energy gamma rays in the energy range of a few tens of GeV to beyond 100
TeV. One array would be located in the southern hemisphere and one in the
northern hemisphere. After a detailed search, we have identified two potential
sites in the USA for the northern array. Both sites are located in northern
Arizona. Here we describe the two sites and the deployment of instrumentation
to characterize them. The characteristics of the sites, in terms of their
atmospheric and climatic properties, are described. We show recent data from
the automated monitoring equipment at the sites and compare these data to a
commercial simulation. Details regarding the facilities and infrastructure
required for the sites are also presented.
