I am not proud of my lack of results in looking over the Great Lakes for #84. My hat is off to Sierra Nevada and I hope we get some more clues.
For #85, I thought that the unique-looking island might be found where wagga would hide something. I guessed that the piece at the top was part of a land mass, putting the island on the southern coast. This turned out to be a wrong assumption that led to a correct conclusion.
What is historical about this particular island? A pirate murdered by his crew?