Before March 1 Red March 1-March 15 Gold March 16-March 31 Brown April 1-April 15 Magenta April 16-April 30 Yellow

Here's the latest snapshot of this spring's monarch migration, thanks to Carol Gersmehl and Kara Elmquist of Macalester College . This map shows the extent of the migration as of May 1, 1997. (Click on the map and it will enlarge to a full-screen image.)