Description: River mile markers are point locations that function as a system to facilitate location referencing along linear streams. The subject dataset is the river mile marker system shown on USGS quad maps for some of the major rivers of the California Central Valley and Sacramento-San Joaquin Delta. As USGS states: "The term river mile is the distance from the mouth of the creek or river to the gage, to the nearest tenth of a mile. The river mile for gages were originally reported in a series of reports. The river mile for new stations are calculated in reference to locations in the index and/or from new topographic maps. River mile distances are not usually recalculated from significant channel changes by flood events, engineering changes, or geomorphic changes in the river channel since the original calculation."The file version was obtained from USGS by DWR (J. Dudas) in December, 2004. For more current versions of these data, contact USGS.