Does anybody know what this yellowish gunk buildup is from? Oil separation? Coolant or fuel getting in there somehow? Is it indicative of anything I suppose is my real question. Thanks

 

Presuming you don't have a minor coolant leak (missing any?) it's just humidity. No shortage of that down where you are. It condenses on cool metal and contaminates your oil with some water. Worse if you make mostly short trips and never get the oil good and hot.

 

x2. i had that happen at a much smaller scale, on my cap. Was worried until I realized i was making dozens of 1/2 mile trips every month and the engine wasn't getting hot enough to get rid of it.

 

Is it detrimental in some way? Should it be cleaned periodically? I put in a new valve cover, so it's clean at the moment. You may have seen this cover before but check it out...

 

Take the Jeep out for a good highway drive to heat the oil up every so often and that'll clear the water out. Also make sure your CCV system is working, not plugged.
We get that pinkish slime all winter long up here. Can't seem to get the oil hot enough, lol...just have to shorten the change intervals instead.