An article from Elkodaily.com says, "Conditions have changed along the Humboldt River since the 1800s. This understatement is especially true regarding travel across Nevada. In the 1800s, the Humboldt provided a route through a dry region. Today, two sets of railroad tracks and an interstate highway travel beside this important river but its water is often out of sight and out of mind. The river’s beginning is generally regarded as a set of springs on the edge of Wells. From there, it flows 310 miles to the Humboldt Sink southwest of Lovelock, dropping 1,675 feet as it does. Actually, 310 miles is map distance, but the river easily flows twice that distance due to the many meanders along its length. Palisade, west of Carlin, splits the river basin into upper and lower parts. Upstream, tributaries add water to the river, swelling its size as it flows toward Palisade. Downstream, tributaries add little water to the river and evaporation causes it to shrink as it flows toward its end. Above Palisade, the river drops 740 feet in elevation over 92 miles, at a gradient of just over eight feet per mile. Below Palisade, the river drops 940 feet over 218 miles, at a gradient of 4.3 feet per mile.... [Near its end], the Humboldt flows through Rye Patch Reservoir for nineteen miles. After exiting the dam, water flows through the river channel and a series of canals to Lovelock. During good water years, water flows on, twelve more miles through the Toulon Drain into Toulon Lake and the Army Drain into Humboldt Lake. Six miles farther to the south, the “river” at this point enters the Humboldt Sink, where evaporation and percolation into the ground claims any remaining water.
For more information on the Humboldt and other Nevada river systems, you can view an interesting series of documents on River Chronologies at http://water.nv.gov/RiverChronologies.aspx.