Martin Marietta - California Aggregates/California Asphalt & Paving District Office

San Diego's building supply store listings run 180 deep, and every one of them has a phone number on file, so calling ahead before a supply run is realistic no matter where you start. Websites are attached to most too, giving you a way to check hours or inventory before driving across town. Zip code 92121 alone holds 28 of these listings, making it the densest pocket in the directory, with smaller clusters spread through areas like 92111 and 92126.

Paid placement isn't active in this category right now, so no listing carries a Sponsored tag, and the order you're browsing is untouched directory data rather than anything bought or boosted. None of these entries are marked verified either. If you own one of these stores and see a wrong number or a broken website link, you can claim the listing and update it yourself, which matters in a category where shoppers are dialing around for materials and won't wait long for a dead line to connect.