The active channel of the Humboldt River was last defined several decades ago and some reaches of the channel are known to have shifted as a result of high flows. Thus, the process of developing the streamflow routing model initially involved the task of redefining the active river channel. High-resolution aerial photography taken in June 1994 was used to define this channel from the Derby Road Bridge near Lovelock (mile 0) to a point several miles east of Deeth, Nevada (mile 431). Secondary high-flow channels and lower reaches of principal tributaries also were defined. The data defining these channels is available on the internet as an Arc Info coverage at <http://water.usgs.gov/GIS/metadata/usgswrd/>. The filenames begin with ha24_hum and hydmain_hum.

The inset maps cover the modeled reach of the river. Click on an inset number below to view a map of the inset and a table of river miles.