Technical Abstract: The establishment of the Rangeland Interagency Ecological Site Manual by the Natural Resources Conservation Service (NRCS), Forest Service (FS), and the Bureau of Land Management (BLM) heralds a new era of rangeland management in the United States (http://www.fs.fed.us/biology/soil/Signed_RIESM_2010.pdf). The manual promises to establish a land stratification system and approaches for describing ecosystem structures, functions, and dynamics in the form of ecological site descriptions, such that they can be applied to all rangelands, no matter their jurisdiction or ownership. The common basis for decision-making will lead to improved coordination and more consistent, transparent, and useful application of science concepts in rangeland management. NRCS has had primary responsibility for the development of ecological site descriptions in the past. This responsibility will be now be shared by all three agencies. At this juncture, we summarize in this special issue the state of the art in the development of ecological site descriptions, recognizing that this art will evolve over the coming decades.