thumb|Winnemucca Lake bed, blue lake to the left is Pyramid Lake
thumb|Petroglyph site 26 Wa 3329, with some of the oldest known petroglyphs in the Americas
thumb|Detail of Petroglyphs – the carvings can be dated because they were covered by tufa layers, after the water level rose above them
Winnemucca Lake is a dry lake bed in northwest Nevada that features the oldest known petroglyphs in North America. Located astride the border between Washoe and Pershing counties, it was a shallow lake until the 1930s, but was dried when a dam and a road were built that combined to restrict and block water flow. It was formerly designated as a National Wildlife Refuge, but its status as a refuge was removed due to the lack of water.
Winnemucca Lake is home to several petroglyphs long believed to be very old. In 2013, researchers dated the carvings to between 14,800 and 10,500 years ago. Either date would make them the oldest known petroglyphs found in North America. The carvings lie within the Pyramid Lake Indian Reservation.
Note: There is another lake, having the same name of "Winnemucca Lake" in California, near the Carson pass (coordinates: 38°40'10.80"N, 119°59'36.59"W).
Geography
Winnemucca Lake is a sub-basin within the Lahontan Basin in northwestern Nevada. which is below the water level of adjacent Pyramid Lake.
History
Winnemucca Lake may have been dry when John Frémont came through in 1843–44.
Frémont's 1844 map indicates that he traveled to the west of Winnemucca Lake and does not map the Winnemucca Lake valley.
The Elko Free Press reports that there was a flood in 1862 that filled the lake to , but Russell states that the level was low in 1862.
In 1865, Winnemucca Lake (then known as Mud Lake) was the site of the Battle of Mud Lake where 29 soldiers from the 1st Nevada Volunteer Cavalry Battalion led by Captain Almond B. Wells (and two civilian guides) killed 29 Smoke Creek Indians. At least two of those killed were women, possibly more. Sarah Winnemucca wrote "I had one baby brother killed there. My sister jumped on father's best horse and ran away. As she ran the soldiers ran after her but thanks be to the Good Father in the Spirit land my dear sister got away. This almost killed my poor papa."
The maximum level of the lake was in the 1880s
In 1936, Franklin D. Roosevelt invoked the Migratory Bird Conservation Act to create the Winnemucca Migratory Bird Refuge as a "refuge and breeding ground for migratory birds and other wildlife." In 1940, the name was changed to the Winnemucca National Wildlife Refuge. In 1962, the refuge designation was removed, making this area the first refuge designation lost because of lack of water.
Petroglyphs
The western end of Winnemucca Lake is home to several boulders carved with petroglyphs that lie within the Pyramid Lake Indian Reservation. The site, officially designated 26Wa3329, was first described by Connick and Connick in 1992. The team, Frances and Robert E. Connick, classified it as unusual, and possibly very early. In 1994, geochemist Larry Benson determined the designs had been carved into a branch form of tufa, a type of limestone. The research showed that the limestone was deposited between 16,200 and 14,800 years ago, but no specific date for the carvings was suggested.
In 2013, a team of researchers from the University of Colorado at Boulder (including Benson) collected carbonate crust and shallow-water algal formations from the site. They then used radiocarbon dating strontium isotope analysis and total inorganic carbon data from a core in Pyramid Lake to establish a window of when the lake level was low enough to allow access to the rocks. Sedimentary cores were collected from nearby Pyramid Lake and subjected to analysis to determine rise and fall of the waterline over time.
Dating of the lowest (newest) carbonate crust yielded a date of 10,200 to 9,800 years ago. The algal formation dating suggested the waterline was sufficiently low from 12,600 to 11,400 years ago. The sedimentary core analysis of Pyramid Lake showed the waterline began to fall about 15,000 years ago, reaching a low approximately 13,300 years ago. At about 13,200 years ago it rose again, and had intermittent low periods thereafter (from 11,300 to 10,500 according to one method, or from 11,500 to 11,100 according to another). The Connick team suggested the petroglyphs may represent meteorological symbols such as clouds and lightning. Benson's team suggests the Winnemucca Lake petroglyphs share several distinctive features in common with the Long Lake petroglyphs that are not found in more recent petroglyphs.