It's officially that time of year, football season is kicking off today and the 49ers will be back on the turf at Levi's Stadium on Monday. 

Before the team became the Bay Area's most successful professional sports franchise, the origin story and the pioneering nature of the 49ers are often overlooked. 

But not for long, as a new book detailing the team's history and revealing some rare pictures will be hitting the stands in 10 days. 

To hear all about it, KCBS Radio anchors Patti Reising and Bret Burkhart were joined by Mark Purdy, Award-winning Bay Area sports journalist and author of "The San Francisco 49ers An Illustrated Timeline."