There is a famous person's brother buried at the starting coordinates.
What year did he die? A B C D
How old was he when he died? E F
Bonus question: How did he die?
Proceed from this point {C} {D+A} {F+E+A} feet, at a bearing of {E} {B-F+1} {C+A} degrees.
At this new location:
What is the large 3 digit number? R S T
What is the OLDEST {Iowa} of the 2 year dates? W X Y Z (hint: 'Y' is a 4)
Using these numbers, calculate {X-W} {S} {Z-R} = G H I
The next part is at 41 43.{H-I} {E-A} {C+D}, 90 31.{F} {E} {B}
At this point you will find further instructions.
Good Luck!