This is a quick 2-stage multi that requires you to do some math. Enjoy the sight of airplanes flying overhead while hunting for this cache.
Stage 1 (Posted Coordinates):
Stage one takes you to a sign. The sign has a year prominently displayed. Assume that the year is ABCD (where each letter is a digit of the year)
Math time:
X = A + D * (B*C/D-1) + C/2
Y = (D - A - C) * 231.472
Project a waypoint from the posted coordiates at a bearing of X° and a distance of Y meters to find the final.