Sacramento police officers responded to roughly 5,000 service calls related to "narcotic activity in progress" during the past three years, according to a Bee review of police dispatch data.
Drug problems were worst in areas near parks, secondary schools, shopping centers and neighborhoods with a lot of poverty.
This map shows, by police grid, the number of calls for service related to illegal narcotics from January 2011 through October 2013.
Data source: Sacramento Police Department
Note: Updated 12/2/2013 at 11:14 a.m. to fix typo showing which years are covered by data.