I have the three book series Gestapo Chief by Gregory Douglas.
Hitler knew of Mueller's plan to escape to Switzerland. He gave him a briefcase with 50,000 Swiss Francs in it. He said, "This is the best I can do for you."
Mueller flew a spotter plane to a clearing near the Swiss border and crossed over.
U.S. representatives went there in 1946 to interrogate him. They asked him about Hitler. Mueller replied, "You could try Spain." Then he added, "Perhaps the Russians could go to Barcelona and ask Franco about him. They might end up buried in an orange grove."
Then he told the Americans, "And if you went there, you might end up in the next orange grove over."
They brought Mueller from Switzerland to the U.S. under Operation Paperclip, gave him a rank of Major in the U.S. Army and he played the piano for Harry Truman.
The reason Mueller was brought here is his specialty was Soviet counterintelligence. And we all know where the Soviet Union is today.
The cover photo of the third book of the series shows Mueller as an old man on a bird hunting trip.
Hard to say exactly where he is buried. Maybe in Arlington National Cemetery. ;)