Correct drainage - maybe raise said area wher you ride and endsure water runs of. correct soil composition -avoid clay or finely graded soils. they tend to swell and cause horribel mud no usage in wet periods
I am building a slope style course, but at one section there is at least a foot or two of mud, what can I do?
use pavers in low spots . dig down 24 inches use rock / 3/4 stone for a base . tamp . sand tamp again. then pavers . space them out 5-10 inch so you can use rock in between . if its heavy flowing water dig deeper use corrugated pipe as a drain to have the water bypass under said trail section . if you cant correct the proplem . reroute it