So the story as told by the Palmer Chamber doesn't sit right with me. Not that the changes are that great, or that the 31 year old memories of a then five year old child aren't probably skewed. But here's the version I remember:
There are creatures that live here in the Matanuska Valley that are not found anywhere else. The Grotto-Lunker and the giant Ice Worm. The G-Lunker is dinosaur that survived the mass exinctions of all the other dinosaurs by living in deep caves. Every year he comes out to see the sun and find food but then retreats to his cave very quickly. While he is very lonely and loves to have fun, he's extrememly shy, and doesn't want to scare people. So every year we have the Grotto-Lunker Parade so that he can come out and blend in with the G-Lunker floats.
The G-Lunker also has friends, the giant Ice Worms of Matanuska Glacier. They also come out during the parade. You can tell them because they look like giant caterpillers with blue & white fur.