The location is on Montgomery St. where the dogs were known to roam.  

Bummer and Lazarus

Bummer and Lazarus were two stray dogs that roamed the streets of San Francisco, California, USA, in the early 1860s. Recognized for their unique bond and their prodigious rat-killing ability, they became a fixture of city newspapers, were exempted from local ordinances and immortalized in cartoons.

• http://en.wikipedia.org/wiki/Bummer and Lazarus