An account is given of a detailed gravity survey carried out on the Salmon Glacier and the adjoining snow field. The reduction of the data is complicated by the extreme irregularity of the terrain and by the fact that the structure of the glacier and the locations of the stations are time dependent. Maps show the Bouguer anomalies, and two profiles are drawn across the glacier and one along its length. The accuracy of the results is discussed in detail; it is concluded that gravity measurements alone can give a very good indication of the shape of a deep-valley glacier and also its approximate depth. Other independent data are necessary to determine its precise thickness.