Stage 1: Get to the posted coordinates and look for a year stamped in the cement. This should put you at the south end of the shelter. Look by the post closest to the woods.
Stage 2: Final container is a regular size peanut butter jar.
Let's do some real simple math...
N = The last two digits of the year stamped in the cement.
X = one half of N, or N ÷ 2
Y = N - 4
Take X and Y to get the final location.
N 44 44.950 + X
W 93 07.848 + Y
Stage 1 disclaimer: The cache owner asserts that stage one is not winter friendly. Depending on the snow fall and/or even if you dig, stage 1 may not present itself during winter months. The attributes reflect this. The last digit of stage 1 may seem to be 1 of 2 numbers. You can use a smart phone camera if you have one to look at the year. The filters on the phone will show the year correctly. Or look at the hint to see which number is more logical.