The maker of Twinkies and Wonder Bread said employees at its 33 factories were sent home and operations were suspended Friday.
The plants include a Wonder Bread plant north of Denver on Interstate 25. The Denver Postreports 160 people work there.
The plant is well known to passing drivers because of its smell of baking bread.
The Irving, Texas, company says a nationwide worker strike crippled its ability to make and deliver its products at several locations.
Its roughly 500 bakery outlet stores will stay open for several days to sell remaining products.