The People's Convoy, similar to the Canadian truckers' Freedom Convoy, left southern California on Wednesday morning.
Around 1,000 semi-truck drivers departed from Adelanto Stadium, a minor league ball park about 85 miles east of Los Angeles.
The convoy is expected to take an 11-day journey to Washington, D.C.
There is also another group called the American Truckers Freedom Convoy, planning a series of convoys from several different states including Montana.
The convoy is a protest of vaccine and mask mandates and was inspired by Canadian truckers.
"It's a little surreal," said Maureen Steele, truckers organizer for the People's Convoy. "The whole thing, to watch this come together on a national scale, to have senators calling you all of a sudden I mean, me. I'm the girl from Montana. People want a part of this. This is historical. Ours is peaceful."
Steele is from Condon, Montana and says groups will be forming mini-convoys, including from Montana to meet up with the big convoy.