In honor of the 167th anniversary of San Mateo County, the Historical Association will hold the third annual “Happy San Mateo County Day.” The theme of this year’s birthday party is the Aughts (decade of 1900-1909). The event will feature craft activities and games of the era.


Poster Contest
The San Mateo County Historical Association is welcoming submissions for the 2023 Happy San Mateo County Day Poster Contest! The theme for this year is Life in San Mateo County in the Aughts (decade of 1900-1909).
San Mateo County residents of all ages are welcome to participate. Posters will be divided into three categories based on the age of the participant. Prizes will be awarded.
More information:
Activity Book
Partygoers will receive the new children’s activity book, Discover San Mateo County in the 1900s.
Click here for an online version of last year’s activity book, Discover San Mateo County in the 1950s.