The Vanessa Migration Project is a citizen science program that has been active since April 2001, as part of the Red Admiral and Painted Lady Research Site (http://www.public.iastate.edu/~mariposa/homepage.html). Citizen observers in North America report their sightings of date, location, flight direction, and other activity of four butterflies of the genus Vanessa (V. atalanta, V. cardui, V. virginiensis, and V. annabella). This presentation will focus on over 300 observations of an extensive Painted Lady (V. cardui) migration that citizen observers in the western U.S. and Canada submitted to our database during spring 2005. The observations we received not only allow us to track the progress of the migration, but a number of observers also submitted daily reports of migration frequency and local flight direction that show the beginning, peak, and end of migratory activity in specific locations. A real-time interactive map interface is currently being developed. This interface will allow users to generate their own maps showing specific types of butterfly activity over particular time periods. We conclude that citizen science reporting via the Internet is an effective way of monitoring familiar and readily identifiable butterflies such as V. cardui and V. atalanta, especially at times when they are very abundant and their activity and migrations are evident to the general public.