The event, which raises funds for police, fire, and military causes, covers 18 states and 3,500 miles in 38 days. The final baton hand-off will occur October 19 at Los Angeles Fire Station 5, with that team of runners finishing up an hour later at the Santa Monica Pier.

Judy Wonderly of Warminster ran a local leg of the 2021 Great American Relay this week. Her time as lead runner took her from Midway Fire Company to Hartsville Fire Company in honor of her husband and her dad.

The 9.4 miles Wonderly covered was just one leg of 415 segments comprising the 2021 Great American Relay, an on-foot challenge connecting Boston to Santa Monica, California.

To date, it has donated more than $50,000 to charities like the Green Beret Foundation, the Firefighter5 Foundation, and Concerns of Police Survivors (COPS).

The idea of organizing a team of literal cross-country runners came from marathoner Vince Varallo of Fort Washington, Montgomery County.

“I founded a running club,” Varallo recalled. “And it kind of gave birth to this event. It really was founded as a Facebook group for runners who ran the Boston Marathon.

“We have 13,000 members from all over the world — from Australia, Israel, Brazil, everywhere. It’s really amazing.”

Organizers set the 2021 route specifically to incorporate sites related to 9-11. Participants in the relay passed batons while running by the World Trade Center, The Pentagon, and the Flight 93 Memorial in Shanksville, PA.

More on the Great American Relay is at its website.