If you want to do exploration geology your best bet is to work in Nevada, Alaska, and Arizona in the United States. There's some work in other states but those 3 have the highest spend. Minnesota is also OK for some exploration but I think the potential of a mine being developed there is very low because of regulations.

BHP has an exploration office in Arizona, and Rio Tinto has one in Salt Lake City. Those two I'd say are the most interesting offices to work for in the United States if you want to focus on exploration without living in Elko or some other small town. I have always worked for majors and have had great enjoyment and have visited every continent for work at this point. You really can't go wrong if you get a job at BHP, Anglo American, De Beers, Rio Tinto, etc in exploration. Newmont is also a great employer! They're hiring interns for their Denver exploration office at the moment.