Nearly pure quartz sands have become increasingly important for oil and gas production. Although used for hydraulic fracturing (“fracking”) since at least the 1950s, the advent of directional drilling and improvements in hydraulic fracturing techniques have led to widespread exploitation of quartz sands that have appropriate properties for use in hydraulic fracturing (“frac sands”). Such sands are present in the upper Miocene to Pliocene upper Bidahochi Formation of northeastern Arizona. Other sand deposits are present in the State, but are not as well suited for use in hydraulic fracturing. This report is a brief review of the distribution and character of sands in Arizona that may have properties appropriate for use in hydraulic fracturing.