The surface of the Saturnian satellite Tethys has been recognized to consist of four major landforms or physiographic provinces: hilly cratered terrain, the Odysseus impact structure, rifts and lineaments (including Ithaca Chasma), and plains terrain. Two alternate scenarios for the geological evolution of the satellite are developed. The first model assumes that Ithaca Chasma and the other rifts and lineaments were created by the Odysseus impact event. The second model assumes that rifting was a result of the freeze-expansion of Tethys' liquid water interior. In both models, the hilly cratered terrain is postulated to be the oldest unit and the plains terrain, the youngest.