Relatively close to all three building sites you will find inexhaustible supplies of clay and quarry stone. Look around at the stone formations in each area, the stone you are looking for is much whiter than the normal grey rocks you normally see. it is usually on the face of a rock formation. If I was to guesstimate I would say they are roughly 4' by 4'.
The clay formations you almost have to be standing right on to see, they are darker brown in color if I recall, look like a muddy patch. I started out at the work bench and walked in ever widening circles until I found them, found them in about 2-3 minutes or so.
I found an iron vein at the Lakeview site, but have yet to discover iron at the other two, in any case the iron is NOT unlimited, it takes nine whacks to clear each vein as usual.. or so I have found.
good luck Foo
Quick to judge, quick to anger, slow to understand. Ignorance and prejudice, and fear walk hand in hand.