Hempirical Evidence is the online home of Nick Johnson, historian, editor, and author of the book Grass Roots: A History of Cannabis in the American West (Oregon State University Press, 2017).

My work is also featured in the following publications/websites:

Agricultural History
The Cannabist (Denver Post)
Colorado Encyclopedia
Colorado Heritage
Nursing Clio
Points (Alcohol & Drugs History Society)
Process (Organization of American Historians)
Public Lands History Center

On this site I offer short essays based on my research, book reviews, and commentary on all things cannabis. It can be difficult to find reliable information on cannabis, but on here I strive to create evidence-based content that promotes intelligent, honest, and productive discussion about one of the world's oldest and most dynamic crops.