How snowpack and snowmelt affect rare fish, wildlife and plants in northern Nevada and the Eastern Sierra

It's no secret that the 2022-2023 winter has been a monumental one for northern Nevada and the Eastern Sierra. According to the Natural Resources Conservation Service's recent Nevada Water Supply Outlook Report, snowpack measurements have “shattered all-time records” across the Great Basin, which includes northern Nevada, and the Sierra Nevada. As of April 1, 2023, snowpacks across northern Nevada were 202-293% of normal, and Sierra Nevada snowpacks were recorded as 218-306% of normal. This epic snow year will mean some epic snowmelt across the region, which National Oceanic and Atmospheric Administration says will bring welcomed water supply to northern Nevada and California, and along with it sometimes dangerous and damaging spring flooding.  

The Truckee River flows out of the Eastern Sierra toward Reno, Nevada, after a snowstorm April 18, 2023.

While it’s too early to know exactly how this year’s snow melt will impact some of the rare fish, wildlife and plants that live in this part of the world, snowmelt – epic or otherwise – is a part of life for many of these species.  

Sierra Nevada bighorn sheep, which may move to lower elevations for the winter, might struggle a little more to survive through the winter and spring due to a deeper and longer-lasting snowpack. However, according to Marcy Haworth, a wildlife biologist with the U.S. Fish and Wildlife Service in Reno, harsh winter conditions are a normal part of life for these sheep. 

“The Sierra Nevada bighorn sheep could be impacted by deep snows due to malnutrition if high winds do not scour off the snow in areas to expose vegetation for the sheep. Avalanches, which can kill the sheep, can also occur,” said Haworth. “Deep snow may also change winter range use, which could lead to more likely or more severe predation. All of these can happen during any winter.” 

“On a positive note, this spring and summer should provide more and better vegetation for the sheep to eat because of all the moisture from the snow,” said Haworth. "Consuming this vegetation through the fall helps to build up fat reserves to get the sheep through the following winter."  

Sierra Nevada bighorn sheep are alpine specialists and live in the Sierra Nevada, generally from west of Lee Vining south to Olancha, California. Because they occupy such a linear range along the crest of the Sierra, winter habitat conditions, record-setting or otherwise, will vary from herd to herd and from year to year. 

In quite the opposite habitat conditions in Nevada’s high desert, small desert fish like the desert dace might not notice that the mountains looming around them have more snow than usual.  

Small desert fish like the dace tend to live in spring-fed pools and streams. “Spring-fed pools may see a slight difference in the amount of incoming flow due to spring snowmelt and runoff,” said Jessica Sáenz, a fish and wildlife biologist with the Service in Reno. “However, those systems are generally dependent upon the groundwater, so they might see no change at all.”  

Desert dace, a small desert fish, live in warm springs and creeks in western Humboldt County, Nevada.

Desert dace are tiny, growing to just three inches, and feed on smaller insects and some algae. They are found only in a small area of warm springs and creeks in Nevada’s western Humboldt County. According to Sáenz, desert dace are pretty tough.  

“They are tough fish! They can survive in waters with low dissolved oxygen, warm temperatures, and high salinity that would kill most other fish species,” said Sáenz. “They are pretty cool and hardy in my opinion!” 

Another hardy fish, the federally threatened Lahontan cutthroat trout, has evolved for nearly 10 million years in the Lahontan Basin and is uniquely adapted to the varied habitats here, living in both alpine and high desert lakes and streams across northern Nevada and around Lake Tahoe.  

It may be too soon to tell how this year’s snowmelt will impact the native trout, said Faith Machuca, the Service’s Lahontan cutthroat trout recovery ecologist, but it is a necessary part of the cutthroat’s life cycle. 

“Spring snowmelt is essential for many stream and river systems across the range,” said Machuca. “Lots of these systems are dynamic and are dependent on the amount of snow in the basin for that year. Spring flow also provides additional spawning habitat in channels that may not flow continuously.” 

“As for big snow years, it’s typically a good thing,” she added. “Trout respond to ‘good’ water years well and that can be reflected in higher year-over-year production and survival, increasing population abundance.” 

Conversely, if the snowpack melts too quickly river and stream beds might get scoured by a lot of fast-moving water, which could negatively impact Lahontan cutthroat trout spawning season noted Sean Vogt, the Service’s Lahontan cutthroat trout recovery coordinator.  

Big snow years also have an impact on our native, and non-native, plant life.  

“For plants like Webber’s ivesia, we are going to see flowers this year, but I don’t expect a rare super bloom,” said Sarah Kulpa, a restoration ecologist/botanist with the Service in Reno. “It should be blooming now in some areas, but in others it’s likely going to be super delayed because it’s probably still under snow, and some of the roads we use to access certain populations might be impassable.” 

A solitary Webber's ivesia flower blooms April 27, 2023, near Reno while snow remains on nearby mountains.

Webber’s ivesia is a low-growing plant that typically showcases small bright yellow flowers from May to July and grows at elevations between 4,500 and 6,000 feet in some parts of Northern California and near the Reno-Carson City metro area. 

It is listed as federally threatened due to habitat loss from urban development, recreation, grazing, wildfire and competition from non-native, invasive plants.  

And it’s those non-native, invasive plants that have Kulpa, and her colleague, Service biologist Sophia Heston, concerned.  

“After a wet year like this one, cheatgrass is probably going to explode across northern Nevada. I expect the same with medusahead,” said Kulpa. “That’s concerning because both will compete with our native plant species for habitat, and they are also really great fuel for wildfire.” 

Fortunately, the public can play a part in stemming the spread of non-native plants like cheatgrass and medusahead. 

“In between hikes or offroad excursions, make sure there is not a lot of cheatgrass or any seeds in general stuck in your shoes, your bike or vehicle tires, or even in your dog’s fur,” said Heston. “This way you aren’t spreading it from one location to another.”

Invasive cheatgrass can easily get stuck in clothing like this person's pant legs and spread to other areas. To avoid spreading cheatgrass, U.S. Fish and Wildlife Service biologist Sophie Heston recommends checking your clothing, shoes, dog's fur and tires after hikes or other outdoor excursions to avoid spreading cheatgrass from one area to another.

Biologists with the Service and partner agencies like the Nevada Department of Wildlife, California Department of Wildlife, Bureau of Land Management Nevada and the Humboldt-Toiyabe National Forest will continue to monitor conditions throughout the spring and summer to gauge impacts to habitat and wildlife. Our thoughts are with the communities and people across northern Nevada and the Eastern Sierra who are impacted by flooding from this year’s snowpack.  

The Reno Fish and Wildlife Office works with our partners to protect and conserve endangered fish, wildlife, plants, and their habitats in Nevada's Great Basin, the Eastern Sierra, and the Tahoe Basin for the continuing benefit of the American people. Learn more about our work here:, or follow us on social media: Instagram, Facebook, YouTube.  

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Endangered and/or Threatened species
Freshwater fish
Invasive species
Rivers and streams