To meet this challenge, you need to find geoacaches that have the first letter spelling out San Luis Obispo. These geocaches must be found within the city San Luis Obispo or open spaces which are surrounded by the city: these include Cerro Romaldo, Bishops Peak. Laguna Lake, Islay Peak, Terrace Hill, and South Hills. A geocache can only be used once and not for a repeat of that letter. For example, the letter "S" appears 3 times in the name so 3 different geocaches beginning with that letter need to be found. One can write a note in anticipation of claiming this find. The difficulty and terrain ratings are not a reflection of that of the actual cache (more like D=2; T=1.5) but the time, effort, and places which one has to go to qualify for this challenge.
I can verify your meeting the qualifications by checking the name and codes. Please list the finds in your log or by bookmark.