Container is at N 40 14.YYX W 76 20.0AB
From parking, walk south along Rt. 322 on the east side of the road and look behind the guardrail on the north side of the creek for a concrete marker (approximately N 40 14.480 W 76 20.193). Count the number of letters in both the person's name and their contribution to this area. Add the number of letters to 61 to obtain the last two digits of the longitude (west coordinate). That is, AB = 61 + number of letters in second and third lines of concrete marker.
Keep walking south (carefully) along the road to the large brown sign at the trail head on the south side of the creek at approximately N 40 14.430 W 76 20.161. On the top of the sign is a 3-digit number. The first digit is X, and the second digit is Y. The last three digits of the latitude (north coordinate) are YYX. Pay attention to the order.
Coords may be bouncy. My phone was not happy in that area and would not settle on coords both the day I put out the cache and when I went back after it was found. Container is within 10 feet of trail. Check hint if stumped. Not an isolated hiding spot.
The trail goes through state game lands. Be aware of hunting activity. However, this part of the Horseshoe Trail is very used by casual hikers. Be very wary of muggles. When placing the cache, I had to pretend to be taking pictures of moss until some muggles went by.
Related information about the creek not needed to solve puzzle:
PDF of 1935 Pennsylvania Angler magazine has a related article on page 2.
Recent article about cleaning up Hammer Creek and restoring it to earlier uses.
Congratulations to albsjudge on the First-to-Find.