It took about seven years and 500 hours, writes Tom Graham for SFGate.

Mission Street was the longest of them.

An excerpt:

“There are 5,321 blocks in the city. The two biggest are the Presidio (block No. 1300) and Golden Gate Park (block No. 1700). Although I’ve walked every block in San Francisco, I haven’t been to the Farallon Islands or Red Rock … or Alcatraz. All within the city limits.

“The more I walked, the more I realized how little I know about my hometown.

“Environmental poet Wendell Berry put his finger on it when he wrote: ‘If you don’t know where you are, you don’t know who you are.’ I guess that’s what I’ve been trying to figure out.

“Wallace Stegner’s essay ‘Sense of Place’ put it this way:

“‘A place is not a place until people have been born in it, have grown up in it, known it, died in it. … Some are born in their place, some find it, some realize after long searching that the place they left is the one they have been searching for.’

“I started this project at age 54. I’m 62 now. I retired from my full-time job and became a grandfather along the way.

“I can truthfully say, ‘I’ve been around the block.’

“I’ve walked by every house, school, church, synagogue, mosque, corner grocery, department store, apartment building, condo, high-rise, warehouse, firehouse, police station, park, lake and playground … past every telephone pole, sidewalk crack, pothole, manhole, cistern, stop sign and stoplight. I’ve passed the majority of the city’s 215 landmarks, mostly in ignorant bliss.

“I realize that my exploration of San Francisco is not over.”