In myth the Thao people originally live in the Ali mountain area, or in another version within Tainan district. A long time ago, a band of Thao hunters found a beautiful white deer in woods. With hunting dogs, they crossed rivers and mountains in order to follow the deer. After several days tracing, when they felt exhausted, but a wonderful lake was appearing in their eyes. Suddenly, the white deer disappeared but left two lines of footprint merging into lake water.

Surprisingly the hunters found a lot of fish swimming in water around their feet. Although they felt hungry, nobody dare to eat those fish. An elder spoke out: “I am old. I will try first. If I am OK, you may eat too.” Then he ate and nothing happened. The others were happy and ate the fish too.

Later they decided some people stayed and some went back home. Those got home told other family members what happened and then brought whole tribe to the lake, where became their new home.