The cache is NOT at the posted coordinates.
I've noticed some beginning geocachers are not realizing this is a "multi-cache" type geocache. You may not have done one of these before.
At the posted location is an informational sign, from which you have to get some numbers and do some math to figure out the actual coordinates of the cache.
You then have to put those new coordinates into your GPS unit or smartphone geocaching app, to guide you to the cache. (It's about 100 feet away.)
If you don't want to do the math, you're in a hurry, and the museum is open, you might ask one of the docents where it is.
HOWEVER, there is a letter combination lock on the cache, and you need to find the right word (which is found on the sign at the posted coordinates) to unlock it.
There are instructions toward the bottom of this description that tells you how to find that 4-letter word.
Congratulations to HuskerMagna for FTF.
This geocache is in front of the Homesteaders Museum, in Torrington, Wyoming.
This cache has been placed with the permission of the City of Torrington and the Homesteader Museum.
"The Goshen County Homesteaders Museum is the home to historical artifacts, historical information, and genealogical resources related to Goshen County from the first settlement in 1834 until Homesteading ended; we strive to collect, present, and interpret the history of Goshen County and its people."
There is a lot of local history inside, but the cache can be acquired whether or not the museum is open.
The posted coordinates will place you at an informational sign about Empire, Wyoming. Empire was an African-American community in the early 20th century.
To find the coordinates of the physical cache:
The degrees and first two digits in the N minutes will remain the same. For your new last three digits; Take the last three digits of the posted N minutes, add the total of the digits of the year the Moses Speese family was photographed, plus 4.
The degrees and first two digits in the W minutes will remain the same. For your new last three digits; Take the last three digits of the posted W minutes and add 3.
To obtain the letter combination to the lock on the cache, find the fourth word in the eighth line (line, not sentence) of the main article about Empire on the sign.
Addition information about the museum can be found here.
You can validate your puzzle solution with certitude.