There is no history, only rumors. Rafters from all over gather together to share their common interest and just have fun. Some people actually set up races and even obstacle courses. Pretty much everything goes. It is a time for everyone who enjoys rafting or even just watching, to enjoy.
Most people go for the entire weekend.
You will see the rvers full of rafts in all sizes and types. My great Grandmother was an Applington. My family is from Eastern Oregon and Idaho specifically Mann Creek area. I'll e-mail you on the subject as you seem to be a fine person. I have always wanted to know more about the Applingtons but live so far away from the original homestead sites that it is hard.