So the end of this last Whipsaw trip coincided with an oil change for me, and as I finished up I was congratulating myself on clearing out all of the mud underneath my skid plates, etc.
I was getting ready to put it all back together when I glanced at the lower surface of my driver's side lower control arm.
Turns out, the bottom-side-forward-end of the control arm has an opening about the size of a matchbook (where the welded end of the lower plate ends just shy of the front of the arm). The *entire* interior of the control arm was *completely* impacted and filled with dirt from sloshing thru the mud. I felt like John Wayne's autopsy doctor

I cleared out nearly a kilo (!!) of dirt that never would have gotten cleaned out on its own from rain, etc.
Just a little heads up if you go playing in the mud; this kind of dirt trap is a real killer for starting corrosion once things get cool and damp.