Well, for my lvl 22 pally, so far Loch Modan seems best for bronze. Starting in Thelsamar, I go south around the lake following the mountains, mining every deposit (copper and tin) I find. When the bags are full, I return to Thelsamar to smelt it all, then follow the mountains back to Ironforge mining all the copper on the way.
Of course, I've just about worked my way out of bronze - I need to find some handy iron deposits now, but I keep getting my butt kicked in the Wetlands!
For a level 60 pally with an epic mount, why not just buy it at the auction house from people like me? :)
Edited, Thu Sep 8 09:36:35 2005 by fledarmus