Head toward the largest lake in this area. There is a small island on its southern part. Just south from here you’ll spot a small waterfall. The skyshard is found next to this waterfall, on a platform, above the lake. From a nearby road, head to the platform, and collect the prize.
In southwestern part of Wrothgar, somewhere between Frostbreak Ridge Wayshrine (to the east) and Great Bay Wayshrine (to the northwest) is where you need to go.