I'm not going to rule out that his work may have taken him to the Gulf lined towns of Texas, on the coast. So maybe that put him in the general area. But being an offshoresman, it's really unlikely that his work would take him to North East Houston, to the Sam Houston National Forest area.
What really freaks me out about this is that this guy obviously has knowledge of some pretty desolate areas/areas easy to dispose of things. First the Whiskey Bay Bridge/the Atchafalaya Swamp. Now the woodsy and sparsley populated Sam Houston National Forest area.
I really doubt Mickey was the only one. However, that being said, she may be...his truck didn't get burned and abandoned until now, afterall.