My wife and I have ziplined on other vacations, but this zip line operation rated among the best we've ever done. They picked us up at our hotel, took us with a good tour narration to their location outside of Denali National Park, and drove us up to their ziplines on side-by-side ATVs.
There, we received a safety briefing and began climbing up the high suspended bridges to the first zip line. Then, we did about 10 different zip lines, each of which were a little different from the other.
The views were great, the rides were thrilling, and the tour guides were committed to ensuring that we had a great and safe time. The owners of this outfit should buy their guides -- Damien and Stephanie -- beers to recognize them for the great job they did!
This was among our favorite activities in Alaska. Go do it!