Secondary calcite shelfstone deposits in caves can be used to precisely measure tilting over geologic timescales. Calcite deposited along the edges of former pools can be surveyed to within a single millimeter, and can be dated using uranium-series disequilibrium. Two caves in the southern Sierra Nevada, California, contain tilted calcite deposits of glacial age. A third cave contains a similar but untilted deposit of older interglacial age. The cave deposits record glacio-isostatic rebound of the Sierra Nevada, following melting of an ice cap ~15,000 years ago. Models of crustal flexure beneath mapped ice thickness reproduce the observed tilting with an effective elastic thickness (Te) of approximately 5 km.