The starting coords for Stage 1 of this multi-cache are tucked into the Logbook of "SGL #43 Berks/Chester Multi" (GC16ET2). There is no actual puzzle to solve. Just back to back multi's.
UPDATE: Since GC16ET2 has been archived, there is no way to get the starting coordinates for this cache anymore. So here are the starting coordinates for this one: N 40° 09.941' W 75° 48.878'
The original "Blue Rocks" (GC18VB4 - now Archived) cache refers to the former name of the Borough of Elverson, PA. The cache owner added, "The BLUE ROCKS themselves are on private property and unavailable to visit". That is mostly true (Please stay off the rocks). But, there is a slice of the BLUE ROCKS on State Game Land. Due to terrain and distance from legal access, visiting the BLUE ROCKS is not a task for the faint of heart. Only attempt this cache if you are comfortable with the possibility of encountering unforgiving terrain. Navigate your path carefully. I avoid all trespassing issues. I also approach out of sight of the future development I had heard is coming to the BLUE ROCKS area (and have seen some evidence of). Under those constraints, I can not guarantee I have picked the best remaining approach, but I am quite sure it is not the worst. This still ain't no stroll in the park. You've been warned. And after all that effort, don't be disappointed when you see it's just a big area of rocks. There is an obvious clue indicating when you are near the BLUE ROCKS. There will also be coords for the nearby BLUE ROCKS view. Remember how you got from Stage 1 to the BLUE ROCKS. Plan on coming back the same way. There are a few tough GPS reception areas. The hints should narrow down the possibilities.
Note: It seems I like to pick spots popular with hunters. A tree stand appeared very close to the original Final. That original container vanished, and a replacement has been moved a little farther away. Now a double tree stand popped up very close to Stage 5.