My 2016 Dutchmen Denali came equipped with Ridgway Sport ST tires in an E-rated 235/80x16 and yes it's Ridgway without the e. You get a few more hits on Google with it spelled that way, but info is still rather sparse. The good news is that they're NOT China bombs. Mine have a YT plant code on the sidewall which shows that they are made by Birla Tyres in India. Having never heard of Ridgway or Birla before, I guess the bad news is that I may possibly own India bombs instead.
I've decided to leave the Ridgways on for at least a year while they're under warranty with the idea of possibly swapping them out for a set of Carlisle F-rated 235/85x16's later on. I have a Tyreminder TPMS to help me keep a close eye on the Ridgways.
If you change tires don't forget to install metal valve stems at the same time. My last trailer was equipped with China bombs and when I lost the first one I had Maxxis tires installed. Within 18 months I lost 2 of the Maxxis tires when the cheap Chinese rubber valve stems failed. I had all my tires dismounted, installed metal valve stems, reinstalled the tires and never had another problem.