Just started a new world/new character as I'm wont to do while bored... and...
Two gold veins right near the surface.
I found a third (but didn't screenshot it) not too much further from that and those three veins gave me enough to make a gold pickaxe while barely breaching into the Underground layer.
I've never seen gold at depths where the surface music was playing 'cept for sky islands before, let alone enough to make a gold pickaxe almost.
Wound up finding enough gold in two trips into the underground (I hit the underground ice biome while doing this too) to make the gold pickaxe, gold leggings, and have enough gold left over for a sword or a bow (I stashed them in the chest, I'll probably just use tungsten on that and save the gold for a watch later).