The Northern Site of the Pierre Auger Observatory

The Pierre Auger Observatory is a multi-national project for research on ultra-high energy cosmic rays. The Southern Auger Observatory (Auger South) in Mendoza province, Argentina, was completed in 2008 with an instrumented area of 3,000 km$^2$. Science results form Auger South motivate the completion and extension of the investigations begun there by constructing the Northern Auger Observatory (Auger North), with a much larger acceptance for the extremely rare cosmic ray events above a few times $10^{19}$ eV. Auger North will have an instrumented area of 8,000 square miles (20,000 km$^2$) in Southeast Colorado, USA. The presentation covers the science of Auger North, the layout and the technical implementation, as well as current R\&D efforts underway in Colorado.