A site-specific measurement of river-level referenced as the height in feet above a designated zero reference point, called the gauge zero, at the site. The zero-reference point is sometimes, but not always, chosen as the elevation of the river bottom. Normally, stage values are always positive. Drought conditions could cause the river level to fall below gauge zero, and the stage reading at that time would be negative. Since each gauge was established independently at each location, the stage reading is good for that location only and cannot be compared to other locations. For example, a stage of 30 feet at Fargo, N.D., cannot be compared to a stage of 30 feet at Grand Forks, N.D. The only way direct comparisons between two gauges can be made is by converting river stage to elevation by adding the stage to the gauge zero elevation.