I don't know where Perez gets his material, but, according to Chris Murphy, they air-shipped the film to Seattle:
"On this point, Gimlin has stated, "We weren't sure from Roger stumbling and falling down on the sandbar and getting up and running...we didn't even have an idea that we had anything on the film at that time...in fact it was doubtful that we did have anything." They therefore decided to airship the film to Al De Atley, Patterson's brother-in-law in Yakima, for immediate processing. It appears the mens' plan was to wait for word from De Atley as to what, if anything, was on the film. This information would dictate their next move. In other words, if they had not captured the creature on film, they would stay longer and try again. The men decided they would both travel to the airport to make the shipment. This task accomplished, they would then return to their campsite. Leaving their horses tethered at their campsite, the two men started out in their truck for a local airport, probably Murray Field in Arcata. On their way, they stopped at Hodgson's store in Willow Creek to talk to their friend, Al Hodgson. As it was after 6:00 p.m., however, the store was closed. Patterson therefore telephoned Hodgson at his home. Hodgson and other friends, including Sly McCoy, thereupon met with Patterson and Gimlin, presumably at Hodgson's store. Patterson and Gimlin then related their experience to their friends. Also, during this time Patterson telephone Al De Atley to inform him of the pending film shipment. Patterson shipped the film to the Seattle, Washington airport for pick-up by De Atley the next day.
Patterson and Gimlin then headed out to an air shipping facility and shipped the film to Al De Atley. As far as we know, only one film roll was shipped to De Atley. It is reasonable to assume Patterson still had the second roll in his camera with sufficient unexposed film for a possible second sighting. The two men then contacted a reporter for The Times-Standard newspaper at Eureka, to whom they related their experience in considerable detail. It is not known if this was a telephone contact or a personal contact. We do know, however, that it took place at about 9:30 p.m. The article appeared in the newspaper the following day, October 21, 1967. The men then immediately headed back to their campsite. By the time they arrived, bad weather was closing-in. By about midnight, it was raining heavily."
http://www.bigfootencounters.com/biology/pgf_history.htm
DeAtley had some pretty big memory lapses on this, but thought he must have chartered a plane. He knew about how much it would have cost.