What was the brainchild of innovative and health-conscious Cal Poly graduates 20 years ago is now one of the nation’s best known smoothie chains with more than 700 locations.

Co-founder Linda Olds had sold the two original local stores to the Jamba Juice company years ago, but repurchased them in October 2009 along with several other SLO County locations to give them the attention they deserve.

SLO Chamber staff, City Council members, and other community leaders will present a special plaque dedication ceremony to Olds and Jamba Juice co-founder Kevin Peters on Monday at 11:30 a.m.

To celebrate that same day, the original store at 17 Chorro Street plans to offer free smoothies from 12:20 to 5 p.m.