The basic features and terminology of terrestrial rock glaciers are reviewed together with associated forms termed protalus lobes and protalus ramparts. Two basic models of rock glacier formation and flow invoke either the creep of ice derived from permafrost or glacial/former glacial activity; a third possible mechanism invokes landslide emplacement. Observations on terrestrial rock glaciers and similar forms suggest that the ice component can be produced via ground ice or from a glacier system. Finite element modeling of simple slope systems containing (1) a continuous ice layer buried by debris and (2) a mixture of ice and rigid blocks can both show creep but with very low rates, especially at low temperatures. Possible Martian examples of rock glacier and protalus lobe features are identified from Candor Chasma by wide-angle Mars Orbiter Camera (MOC) imagery, although the topography does not allow unambiguous interpretation. Some possible ways in which MOC and Mars Orbiter Laser Altimeter (MOLA) and other Mars orbiter data could help future interpretation of rock glaciers, related protalus landforms, and ice presence are discussed.