The grounding-line region of Rutford Ice Stream was surveyed from the ground during 1978–79 and 1979–80, and from the air in 1980–81. Maps of surface elevation and ice thickness of an area of 1 000 km2 allow the grounding line to be delineated and show that the ice stream consists of several distinct fingers of thick ice trending parallel to the flow. In one area, the floating ice is more than 2 000 m thick. Hydrostatic tiltmeters were used to pinpoint the grounding line. Repeated survey of a network of stakes gave velocity and strain-rates for both longitudinal and transverse profiles. Radio echo-fading pattern studies showed the ice to be completely sliding near the grounding line. Modelling of the ice stream, using steady-state theory, shows that the bottom melting rate is around 1.8 m a−1. The small surface and bottom gradients imply that the position of the grounding line may be sensitive to small changes in ice thickness.