How was jewel cave formed?

Jewel Cave; currentlysecond longest cave in the world - 157+ miles of surveyed passages. NearCuster, in South Dakota's Black Hills. (Source: google)

The photographs of its show-cave section on one of the references show it to be a well-decorated karst cave,so it results from normal limestone-cave development processes; and if it contains streams, the stream-passages are still beingformed by those streams.