District 51 is all the portion of Los Angeles City which is described as follows:
From a point commencing where the most northerly boundary of the City of Los Angeles intersects with the Golden State Freeway and following on the city boundary in an easterly direction where the boundary first intersects with the boundary of the City of Burbank; thence continuing southeasterly along the Burbank City boundary to its intersection with Barham Boulevard; thence in a southerly direction on Barham Boulevard to its intersection with Cahuenga Boulevard; thence in a southeasterly direction on Cahuenga Boulevard to Mulholland Drive; thence along Mulholland Drive to the Los Angeles City boundary; thence following the Los Angeles City boundary west and northerly until the boundary intersects with the Los Angeles-Ventura County line, thence following the Los Angeles County line north to the Kern County line, and east to the Golden State Freeway, and thence in a southerly direction on the Golden State Freeway to the starting point at the Golden State Freeway.
Source:
Section 3901.5, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=FAC§ionNum=3901.5..