What are the dimensions op the map? You can set a Hunter for 500 meters(?). But how do you see which area that is?

That tin deposit farthest to the south and west, the one near the river border of the map.. West of the first Y in the road heading south from Blackridgepool..
It has a large chunk of iron sitting next to it that doesn't show up on the map or have an icon for mining. It's a giant red rock next to the tin deposit. If you line up where you can access the tin icon, but are facing the iron rock, then you can easily mine iron from it.
Cheers!

Very helpful.