Hydaticus cinctipennis.
Photo: 05/27/18, noon.

Hydaticus cinctipennis can be characterized by its brown coloration of the body and the presence of defined lateral yellow margins on the elytra. I found this specimen and some of its buddies in the (water-filled) bed of my truck. Unfortunately they were quite successful in hiding under plant debris, which made it even harder to take a decent photo.  
bug guide (this photo):