In 2000, Colorado voters approved a constitutional amendment that legalized medical marijuana. As State Health Department regulations and Federal policy about enforcement have changed this year, local and state officials have been forced to grapple with the rapid growth in the number of dispensaries and registered users. New court rulings have also complicated the scene. State health officials estimated that they would receive 23,000 applications for medical-marijuana cards in 2009, up from 4,720 in 2008.