It turns out that I did get digipeated by the ISS after all.
Ed AD7FC reported that he heard the EDDY-8 beacon repeated by the ISS On Timberwolf Peak near Yakima WA. He replied back with a message, but due to my hardware problems, I never decoded any packets from the ISS.
On looking at the raw packets on aprs.fi, it appears that not only was I being digipeated by the ISS, I was also being heard direct by the W6MSU-8 satgate in Stockton 240 miles away.
We may not have had an end to end golden packet for the PCT this year, but at least one packet could have been heard from Mexico to Canada.
Here is a photo album of the hike and summit of Mt. Eddy:
My operating station was in the shelter of the remains of the old fire lookout. It gives new meaning to the term "Ham Shack".