Alana T was right. Sorry I missed the review before we rented the dirt bikes. 413 river bed trail is full of sand and loose gravel making the experience more work than fun. 413 then turns into 2124 trail which is sandy and uphill and filled with switchbacks. Even more work and even less fun. Once you get to the top the trails are hard pack and actually start to be fun with great views. Unfortunately the only way back is either the way you came or an even sandier version of 413 trail.
To make matters worse, I got to pay another c-note for a few loose bits of plastic that was holding this old dented ride together.
The only saving grace was the receptionists that got us going. That earned them an extra star.
The RZR folks on the other hand were having a great time. Suggestion, rent an RZR from these folks and skip the dirt bikes.