Here is a great film of the Explorer Post 20 from Los Alamos, New Mexico, doing a self guided trip through Grand Canyon in 1975! My thanks to Stretch Fretwell for all the river advocacy he has done over the decades!
I also loved the double oars and the decked canoe. Technology has certainly changed on the rafts since then. Great video. I launch for the first time on the Grand next Thursday, so this video was great for inspiration.