Thanks for the reply. I'd say that a really dull colored tiger salamander is the closest thing I've seen pictures of to what I saw in person other than a hellbender. A few differences though, the one I saw:
It didn't seem to use its legs for much. It mostly used its body to propel itself. It certainly wasn't fast. I could have easily reached down and picked it up -- not something I normally do when I see a creature I don't recognize, especially when it's the size this thing was.
The chicken house probably was built in the 40's and I own no chickens.
Believe me, I've looked through those bricks and around the chicken house. My #1 concern at this point is I don't want to harm it in any way. Of course, knowing what I know now, I'd sure like another shot at seeing it again. That seems doubtful at this point.
By the way, I do have a small pond within 50 yards of that corner of the chicken house. I have no livestock and purposely use very little pesticides, herbicides, or chemicals on my property, so it's always full of frogs. They get so loud in the spring that it's hard to hear myself think.