CA District 52 is located in Northern California and covers most of the San Francisco Peninsula and contains member leagues from San Mateo County and Northern Santa Clara County. San Mateo National Little League is a member of District 52 ("D52"). 

Following the completion of the Spring regular season, SMNLL selects All-Star teams to represent us at the District level during the summer. 

D52 hosts All-Star tournaments for 5 different age groups (10U, 11U, 12U, 13U and 14U). The winners of the D52 Tournament for each age group advance to the California Section 3 tournaments. The winners of the Section 3 tournament advance to the Northern California tournament. For all age groups, except 12U, that is the final tournament of the summer. 

For the 12s, the winner of the Northern California tournament advances to the Western Regional in San Bernadino, CA. The Western Regional brings together the LL champions from Arizona, Hawaii, Nevada, Northern California, Southern California, and Utah who compete for the right to advance to the Little League World Series in Williamsport, Pennsylvania. The Little League World Series is nationally broadcast annually on ESPN and ABC.