Very nice specimens. My friend and I bought a collection last year that had a bunch of gold from Central America including gold crystals. The crystals were amazing. Until seeing them I didn't even know gold could crystalize like that.
I have a cool little specimen on our shop right now that looks like it was river tumbled, but on closer inspection you can clearly see it's natural and not tumbled.
As for getting out there, ya, there are still tons of gold and gems out in those hills!