There is a high degree of probability that the Zodiac Killer was using the Boise Cascade Incline Village advertisement as a template to identify the Clair Tappaan Lodge "Sierra Club" alongside Interstate 80 and Donner Pass Road..So at the very least, the Zodiac Killer had referenced a location on the northwest side of Lake Tahoe, heading towards the location where the remains of Donna Lass were eventually found on December 31st 1985 and early January 1986 (reported in the newspapers as 1986).
His previous communication, the Los Angeles letter, was not only postmarked the same day as the general release in the USA of the movie "Vanishing Point", but the letter mimicked the wording from the January trailer of the car chase movie, in which "a radio host from KOW stated "And there goes the Challenger being chased by the Blue, Blue Meanies on wheels. They want to get him and put him away, but there'll have to catch him first". The author of the Los Angeles letter (Zodiac) stated "If the Blue Meannies are evere going to catch me, they had best get off their fat asses + do something". The beginning and ending of the movie (in which the main protagonist, Kowalski, met his death) was portrayed as occurring in Cisco, California (alongside Interstate 80), where the remains of Donna Lass were found close by.
Consequently, we have two consecutive Zodiac Killer communications (9 days apart) containing material that can be linked to Interstate 80 on the northwest side of Lake Tahoe. Clair Tappaan Lodge and Cisco are 10.55 miles apart (as the crow flies). Of course, the appearance of Cisco in the movie may have had no bearing on the Zodiac Killer when referencing the Vanishing Point movie in the Los Angeles letter (if you believe the premise of the movie connection). It could easily be argued that either connection is fortuitous and coincidental.
Only the skull and jawbone of Donna Lass has reportedly been found, which could suggest her remains were dispersed by wildlife, or she was murdered elsewhere, dismembered and her remains scattered in the area. The Zodiac Killer didn't necessarily imply a burial site on the Pines card, only that her remains may have been found "around in the snow" (if that is the correct interpretation). PART ONE. PART THREE