The United States Geological Survey has a fantastic PDF document just chalked full of information on Bristlecone Pine trees. The article is titled “Growth-Form Characteristics of Ancient Rocky Mountain Bristlecone Pines (Pinus aristata), Colorado“. This article is specific to Colorado but it had great information that may be useful in other states. I have added the article to the Pines Bonsai page under Conifers Bonsai and Bonsai Tree Information pages.

Photo courtesy of United States Geological Survey