Whistle Lake is located in the northwestern region of Elven Island. It is the home to Whistle Lake Oil Frogs and aggressive Whistle Lake Crabs which are hard to spot in the water and attack unwary travelers who don't use the bridges. It is believed that the reason the Sabineans do not cross Whistle Lake to bother the other inhabitants of the island is that they fear the pinchers of the Whistle Lake Crabs.
On the western shore of the lake, Dimuphalat will give you a series of quests, including a daily quest once you have completed the Bring Some Improved Food quest. On the eastern side of the lake, Lamot, the leader of the Fellowship of the Holy Stone, will give you a series of quests involving the Sabinean Cave. There are Hill Bear Cubs on either side of the lake for the [Daily] Those Bears Again!.