The recent development of horizontal drilling techniques and application of hydraulic fracturing to horizontal wells has dramatically increased oil and gas production in the U.S., notably in areas where extensive organic-rich shale and calcareous shale deposits are present. Shale and limestone formations that contain hydrocarbons without sufficient porosity and permeability to yield oil and gas with conventional drilling techniques are being reconsidered in light of these technological advances. The Mancos Shale in the San Juan Basin in northwestern New Mexico has become a target of interest because the new technologies have unlocked the potential of unconventional resource plays like the Mancos Shale. Broadhead (2013) described the Mancos Shale oil and Mancos Shale gas plays in New Mexico at the San Juan Basin Energy Conference on March 18-19, 2013. In this report we briefly review the geology of the Mancos Shale in Arizona and consider its potential to yield hydrocarbons with horizontal drilling and hydraulic fracturing.