08/26/2011 10:16 am ET Updated Oct 25, 2011

Montana PBS Investigates The Science Of Cannabis, Medical Marijuana

Medical marijuana has seen an erratic history of late: An appeals court in Michigan recently restricted access to medical marijuana there; Montana voters legalized medical marijuana in 2004 but have also had access stymied; Colorado voters, meanwhile, may see an all-out legalization ballot initiative in November; Others speculate Massachusetts may seek to legalize the drug as well.

Given the diversity of opinions on legalization and speculation about marijuana's efficacy as a medicine, we were particularly interested to see Montana PBS's hour-long documentary 'Clearing the Smoke: The Science of Cannabis.' Though the video originally premiered in February, as the Colorado Independent points out, smart policy is built on sound information.

WATCH the first 20 minutes of the Montana PBS special 'Clearing the Smoke: The Science of Cannabis:'

Watch the full episode. See more MontanaPBS Presents.