The cache is not at posted coordinates. You need to do the Lancaster County Benchmark Adventure for the coordinates.
You can search for benchmarks at National Geodetic Survey Data Explorer where you can search by the PID (Permanent IDentifier) Station Name or map location. It isn't super easy to use, but once you get used to the interface, it works. You can get to the datasheets. There are no logs, and few pictures. You can identify Benchmarks by PID to be found on the Data Sheet, and the DESIGNATION on the Data Sheet and Benchmark Disk.
Some geocache's related to benchmarks: What's a Benchmark?-GCA3J8F, Hunsicker Mill Bridge Benchmark-GC9MZQ8, Benchmark A-213 (KW0624) - Lititz, PA-GC6Z06R. You can log some benchmarks on Waymarking, using the category of US Benchmarks. can be reached from the geocache page.
In order to find the coordinates for this cache, you must complete The Lancaster County Benchmarks Adventure Lab. Use the Adventure Lab app to visit the 5 lab cache locations and fill in the missing numerical values from the completed journal pages.
N40 08.ABC ---- W76 19. 6DE
The cache can be found on back of 1913 boundary marker.
Congratulations ratjam First to complete the Lancaster County Benchmark Adventure