You'll want to print out a copy of these clues and bring them; the coordinates alone are not enough to find the final geocache. You'll also want a pencil/pen to write down the intermediate clues as you go along, and a compass if you want to try orienteering.
The six intermediate locations you'll need to visit first are all points on the permanent orienteering map located in the park. The total distance you'll need to cover is less than two miles, and would be roughly equivalent to an 'orange' orienteering course.
You can either find them using their coordinates and a GPS, or by picking up the Orienteering map ($1.50) in the Nature center, and marking the points used (2,3,4,5,13, and 25) from the master map. The master map is located just inside the door to the museum office, in the back room of the nature center.
At each one of these points, you will find a metal red and white orienteering flag permanently mounted on some local object, along with a letter and a number. Ignore the number, and write down the letter you find in the space below:
Point 2: N41 15.291 W73 35.227 = _A__ (X1) (temporarily missing)
3: N41 15.137 W73 35.057 = ____ (X2)
4: N41 15.039 W73 35.014 = ____ (X3)
5: N41 14.978 W73 34.928 = ____ (X4)
13: N41 14.835 W73 35.142 = ____ (X5)
25: N41 14.637 W73 35.004 = ____ (X6)
When you've found all six points, look up the values for the letters in the table below. A=1, B=2, J=1, etc.
X1 = ___ X2 = ___ X3 = ___
X4 = ___ X5 = ___ X6 = ___
Then, plug these values into the two formulas below, which are used to determine the coordinates of the final geocache.
The coordinates are:
N 41 14.AAA W73 35.BBB
AAA = 42*X1*X2 + 9*X3*X4 + 91*X5*X6 + 150
BBB = 7*X1*X3 + 7*X2*X5 + 7*X4*X6 + 20
This should be within 20 minutes walk from the other places you've been. Good luck!
Useful Notes (with credit to those who mentioned these facts in the logs): You may need to pay for parking; normally $8, $4 with a park pass. The museum with the master orienteering map is not open on Mondays and Tuesdays.