In the case of the 'Pines' card, the author chose a postcard of "an artist's rendition of houses among the trees at a Boise Cascade Company project at Incline Village, where construction has just begun on the development". He then directed us to "pass lake Tahoe areas" to an area by the "Sierra Club". If we follow these simple instructions we find ourselves at two locations in close proximity. The first is Clair Tappaan Lodge on Donner Pass Road - but more importantly - the second is Donner Memorial State Park (preserving the site of the Donner Camp, where members of the ill-fated Donner Party were trapped by weather during the winter of 1846–1847, resulting in 39 deaths). Bearing in mind the 'Pines' card was thought to have been mailed by the murderer of Donna Ann Lass, this may be the motivation behind its design. The author was pointing us towards the Donner Memorial to signify the forename of his murder victim. Of course, this could be a simple coincidence and not the intended meaning behind the postcard. Therefore, if we can find the identical design or meaning within its sister card, mailed on July 13th 1971 (just 4 months later), then we can just call it a double coincidence, or quite possibly accept that the designer fashioned them both with the intention to give us the forename of the murdered women in question.
Fortunately for us, another coincidence exists. Sitting in the Monticello neighborhood is Oak Hill Memorial Park, where one of Zodiac's previous claimed victims is interred. The Zodiac Killer insinuated his involvement in the brutal stabbing of Deborah Gaye Furlong (14) and Kathy Ann Snoozy (15), who were found murdered on August 3rd 1969 in the Bay Area of San Jose. By writing "Aug" on the November 8th 1969 'Dripping Pen' card, he was effectively laying claim to the Furlong and Snoozy murders - and the very reason he chose the location of Monticello on the July 13th 1971 postcard. Not only was Kathy Snoozy buried at Oak Hill Memorial Park, but she shared the same forename as Kathy Bilek. The Zodiac Killer was leading us towards a memorial park and forename in both postcards - Donna and Kathy.