Sounds like Arn's got the winner for low tech - if it was good enough for the Egyptians then why not for us?
I've got a really good roller setup that Marshall did for me when he still had his fab shop but... The best, low-cost, and simplest fixed-mount option I've seen is a steel pipe with a slightly larger PVC pipe as a sleeve over it. One moving part, water won't hurt it, slight warping isn't a problem, etc. I've even seen a setups like this ranging from 4" steel pipe to one using 1" galvanized pipe.
Doubtless you could rig this up so it could be bolted on in Feb. when the Salt season starts and taken off in November at the end of the season after you get back from Big Bend, that way you'd have the trailer to do home improvement projects with during the rest of the year.