A group of local firefighters and military vets are now off on a 40-day bicycle trek across the U.S., riding from the "Bay to Brooklyn" with plans to arrive in time for the 20th anniversary commemoration of September 11th in New York City.

The group of a dozen firefighters and vets left Sunday from Santa Clara, led by retired Santa Clara firefighter Derrell Sales. As he tells KTVU, "We have people from Arizona, military, state fire agency, local fire agencies. We're doing this because we want to remember the 343 firefighters who died on 9/11."

They plan to ride about 80 to 100 miles per day, arriving in New York by September 9.

"For many of us, we remember what happened on that day, we remember where we were, we remember the sounds, we remember the smells," says Sales, speaking to NBC Bay Area before the Sunday departure. "For some, they still haven't healed from it."

The group left from Fire Station No. 2 in Santa Clara, and the city's mayor, Lisa Gilmor "We're with you every mile. We'll watch you the entire time and just know it means so much to us and so much to the families affected by 9/11."

This is the second time this group has made the cross-country journey, having done a similar ride in 2011 to commemorate the 10th anniversary of the attacks.

As they say on the Bay2Brooklyn website, "This is our 2nd event and we invite you to follow us as we ride and connect with everyone across this great country."

Their daily routes are all here, and the trip started with a ride to the San Francisco Ferry Building on Sunday, and then today they rode from Vallejo to the California Firefighter Memorial in Sacramento. From there, they take a couple of legs by car, first to Redding, and then to Eugene, Oregon, and from there they get on their bikes tomorrow to ride 52 miles to Rainbow, Oregon.

By September 6, they plan to be in Washington, D.C. for a day to commemorate those who died in the Pentagon attack.

If you want to donate to their ride, you can do so here.