Anyone with a hand-held GPS and a sense of adventure can participate. The geocacher first picks up an official MML passport, then plots coordinates found on the MML geocaching Web site, uses their GPS to locate a treasure or "cache" (usually a trinket or unique item from the locale), and then enters the code word for the site in their passport. There are 78 locations along the statewide trail, including two in Baltimore. The first 500 geocachers to discover at least 2 caches in each of the 11 districts across Maryland will be awarded a collectible coin (also available at Federal Hill Main Street).
So far, 20 geocachers have come to Federal Hill from neighboring counties to collect passports. Five others have completed the trail and collected the coveted coins. Many are families who want their children to learn first-hand about Maryland's unique cities and towns, but adults enjoy it, too. "We enjoy learning about different places and their history," said Chris Ryan of Annapolis, the first person to collect a coin at Federal Hill Main Street.