Marianne Scott Lincoln was the 14 year-old girl who told this story, and I broke it on the Mountain News in 2011 after she told me the tale in August.
She was quite adamant about what she told me. She said she listened on her family's radio in the hanger, and listened to the Seattle Center's side of the conversation. She never heard the cockpit, apparently.
Marianne started the conversation by overhearing me tell another person about my book on DB Cooper, and when I mentioned that the skyjacker wanted $200,000, Marianne jumped in and vociferously argued that Cooper had wanted $400,000 and that there was an argument over the radio. Eventually, the skyjacker was talked down to 200K.
Marianne was resolute about that.
She also said that she thought the plane was far east of V-23 and turned left at Gresham and headed up the Columbia River Gorge. She wasn't absolutely sure on that, but that was her basic recall.
Marianne never told me that she heard 305 pass overhead, even though Shady Acres airport is kind of under the flight path. The person who did tell me that she heard 305 that night was Dona Elliott, who said she heard it plain as day and estimated it was flying at 3-4,000 feet. Later, Dona told me it was raining so hard that she couldn't see across her street at her home in Amboy.
I see that Farflung had lots of trouble corroborating Marianne's story based on antenna heights and radio reception. I have no knowledge about that, and had a bit o' trouble following his arguments. Maybe I need another cup of coffee or more/less meds.....
As for dumping DB Cooper in the brink, Bill Rataczak told me that was his CLEAR intention, and was talked out of it by Paul Soderlind upon the orders of Donald Nyrop, who simply wanted his plane back without any fuss.