Thunderbird Falls is one of the most popular hikes in Alaska. The 0.8 mile (1.6-mile round trip) hike branches into two endpoints. The easier route ends at a viewing deck near the top of the falls, whereas the other harder branch leads to the bottom of the falls.
From home, you can hike the trail virtually on your computer with 360-degree views on Google Maps, as Google actually hiked the trail with their Google Street View mapping equipment. No, you cannot find the cache on the virtual hike.
You are looking for a small to medium size cache, with some swag and trackables if you want to partake while you get mischief managed. It is well camouflaged from muggles, so don't believe your eyes too much if you think it belongs there.