By the early 1800s, the Northern Paiute lived near the lower Carson River and the present Stillwater National Wildlife Refuge, while the Washoe people inhabited the upper watershed region.

[10] The Washoe peoples that had residence in the Carson Valley were also divided into a separate group and called "Pau wa lu".

[14] Virginia City, Nevada, along the lower watershed, was home to the world's greatest silver rush, the Comstock Lode in 1859.

[15] In the early 20th century, the Newlands Reclamation Act was passed to bring irrigation water into the region for agriculture.

[16] The Truckee-Carson Irrigation District was formed in 1918 as part of the project to divert water from the Truckee River to the Carson Valley for agricultural use.

In the middle watershed, the river runs generally northeast from Carson City across Lyon County, past Dayton.

Downstream from the dam (in the lower watershed), much of the water is used for irrigation in the vicinity of Fallon, with limited flows continuing northeast into the Carson Sink.

This is Nevada's only NPL site and is being jointly managed by NDEP and the U.S. Environmental Protection Agency 9 (EPA), Region IX, in San Francisco.

The methylmercury, due to its specific properties that include it being fat soluble, can lead to bioaccumulation and biomagnification of mercury in Carson River Aquatic wildlife.

Small children have the highest risk due to developing bodies and their propensity for ingesting soil while at play.

[26] The EPA and other scientists studied residents of contaminated areas and found no direct evidence of increased metals in blood, hair and urine samples.

OU-2 is defined as the water, sediment, and biologic resources of the Carson River, Lahontan Reservoir, Washoe Lakes, Steamboat Creek, associated irrigation ditches, and the Stillwater Wildlife Refuge.

The most significant health risk posed by mercury in OU-2 is the consumption of fish and waterfowl from affected lake and river systems.

The LTSRP provides guidance for land development activities (both commercial and residential) to help assure site CoCs do not impact human health and the environment.

[28] During the Comstock Lode a new, Washoe "hot-pan" amalgamation, the process was created specifically to treat Nevada ore in 1861.

[30] In the lower reaches of the Carson River watershed, the Stillwater National Wildlife Refuge hosts large breeding colonies of white-faced ibis (Plegadis chihi) and is frequented by non-breeding American white pelicans (Pelecanus erythrorhynchos).

The Carson River watershed also provides habitat for many smaller species of birds such as tree swallows (Tachycineta bicolor) and house wrens (Troglodytes aedon).

[31] The Washo people who lived in the eastern Sierra with hunting grounds extending as far west as Calaveras County, have a word for beaver, c'imhélhel.

[35] Peter Skene Ogden, on a Hudson's Bay Company expedition to the terminus of the Humboldt River, wrote in his diary on May 15, 1829, "In no part have I found beaver so abundant.

"[37] Adams' account is consistent with a 1906 newspaper article in the Nevada State Journal that the Mason's Valley of the nearby Walker River in Yerington, Nevada was well known to "the early trappers and fur hunters...Kit Carson knew it to the bone...The beavers of course were all trapped long ago, and you never see an elk nowadays..."[38] During the Comstock Lode mining operations (1860–1890), extensive amount of Mercury (Hg) was released into the Carson River, Lahontan Reservoir, and Stillwater National Wildlife Refuge.

In one study, electrofishing was conducted at four different locations along the river to capture and sample fish for traces of Hg toxicity.

[41] Carp, golden shiners, species of sucker-fish, and crayfish all showed Hg toxicity in samples taken from the four testing sites.

[42] The Carson River is a trophy trout stream that offers ideal conditions for both fly and spinning anglers.

Development along the river in Douglas, Carson City, and Lyon counties has limited public access in some areas.