Seeking "Official" delineation of North American mountain ranges?
UNEP-WCMC came up with a definition using altitude and slope and a few other criteria that resulted in 7 classes all defined as mountainous regions. The info below is from the 2002 version.
Data:
http://www.arcgis.com/home/item.html?id=a068913914cd4fecb302b9207a532d1a
Definition of mountainous regions:
http://www.biodiversitylibrary.org/item/97616#page/76/mode/1up
Citation:
UNEP-WCMC, 2002. Mountain Watch: Environmental Change and Sustainable Development in Mountains. UNEP-WCMC. Cambridge, UK.
Updated links (August 22, 2019): The linked data on ArcGIS.com seems to be be dead. This page has links to two similar datasets from UNEP-WCMC. Follow these links to download the datasets directly from UNEP-WCMC (you will need to fill out a short form to gain access):
- Mountains and Forests in Mountains, 2000
- Mountains and Tree Cover in Mountain Regions