We investigate the potential of local earthquakes to generate tsunamis and seiches within Lake Tahoe. We calculated the long wavelength oscillations generated by 3 hypothetical Mw>7 earthquake scenarios for faults with normal slip directly under and outside the lake basin. The scenarios involving fault slip under the lake are the North Tahoe-Incline Village and West Tahoe-Dollar Point scenarios. The Genoa scenario involves a fault that crops out 10 km east of the lake. Faulting beneath the lake generates a tsunami followed by a seiche that continues for hours with waves as high as 3 to 10 m. The seiche potentially threatens low lying lakeside communities and lifelines. We also compare the spectral characteristics of synthetic tide gauge records with wind swell observations. The fundamental mode calculated for a seiche is consistent with the wind swell observations. ¿ 2000 American Geophysical Union