The stop ids actually _do_ have some sort of order to them. It looks like some time ago they took all of the stops, put them in alphabetical order and then numbered them accordingly. Stops on A Ave, Abernethy, Alberta tend to have very low stop ID numbers (< 75) while stops on Woodstock, Yamhill, Yeon tend to have high numbers (~6400). MLK stops are located in the "U" section (5885 = Umatilla then 5886 = MLK & Ainsworth) because it used to be named "Union Ave." Numbered stops are after the alphabetical stops. New stops are generally at the end, but sometimes inserted in random places in the middle.
Go see for yourself