I've completed 4 Seattle to Portland rides from 2011-2015 planning on completing my 6th STP this July. Other rides that I've completed are Ride2Recovery Challenge rides in Texas, Washington DC, and California. I have ridden the STP with a great organization Outdoors For All. I will be riding with them again this year my 6th year in a row doing the STP.
Cascade is a great organization.
Lemond Tourmelet 51 CM