Yes, there are a handful of geocaches out here but none of them quite out this far. And none of them show the beauty of this area like this one. For the nicest hike, I'd suggest taking the high road from parking, staying straight whenever you have a choice until you get to the second stream crossing. Make a right and head down to Gunpowder Falls and head right. To see a bit of hidden history, you can cross at the second stream crossing and then head to the Gunpowder where you will see all that is left of Hoffman's Paper Mill. There is an old stone wall and part of a dam, likely built between 1775 and 1803. The stream crossings (Walker Run and Silver Run) aren't great so wear good boots or prepare to get wet. From the stone wall, follow the Gunpowder upstream until you start to see the beautiful huge rocks and hemlocks that make up the Hemlock Gorge. GZ is up the hill to your right. On the way back, follow the rocky trail along the river for some of the most beautiful views I've seen in the Baltimore area. It will dump you out close to parking. Total hike is about 3.5 miles.
Container is a small, square lock n lock. I suspect the signal bounce in this area is significant so your coords may differ from mine. Feel free to take and post your own set of coords for others to use. I'll update the posted if enough people provide better coords than I have given.