The puzzle:
The cache is hidden a short walk from posted, so the degrees and minutes are as posted. You will need 6 numbers to make up the decimals of the two coordinates. To get these numbers you need to count some of the features in the mosaic built into the pavement.
N 53 33.ABC W 113 33.DEF
A = The number of black circles in the pot (not the pedestal) that AQUARIUS is holding
B = The number of stones in the E for ARIES
C = The sum of the black stones that make up the lips of both GEMINI twins.
D = The number of white stones in the circle (pivot) between the LIBRA scales
E = The number of white stones in the left claw of SCORPIO
F = The number of stones that makes up the first S in SAGITTARIUS
Check your solution
As of about December 2018, they've put up a new construction fence and really look like they're refurbishing the building! ... Everything was open and available last time i was there, so removed the 2 gimmes in the text :)