A wildlife crossing bridge built for local bighorn sheep over Interstate 11 between Boulder City and the Hoover Dam. Tuesday, March 14, 2023.
Friday, Oct. 27, 2023 | 2 a.m.
Slow and steady may win the race, but for Nevada’s desert tortoises, it could mean death on many of the state’s highways.
If you look carefully on your next road trip, you might notice some of the old wash tunnels underneath these roadways refurbished for animals to pass through. These wildlife crossings come in many types and sizes, but their purpose remains the same: to protect animals from being hit by cars.
And more could be in the works in the next decade thanks to a $5 million appropriation included in Assembly Bill 112, which was signed into law in May by Gov. Joe Lombardo and requires the Nevada Department of Transportation and the Nevada Department of Wildlife to construct wildlife crossings in specific areas.
“(AB 112) helps kind of highlight some of the areas that aren’t maybe a big safety need, but more of a conservation need and opens up some additional funding,” said Nova Simpson, a biological supervisor at the Nevada Department of Transportation. “In the past, we’ve been traditionally looking at safety, but we are also trying to consider a lot of these other ecological needs as well, especially with species that are threatened and endangered.”
Roads affect ecosystems
Although these look like the typical pedestrian bridge you’d see on the Strip, wildlife crossings are designed to mimic the surrounding environment using natural elements like grass, dirt and shrubs.
And they are vitally important, wildlife officials say.
That’s because dangerous roads affect ecosystems by increasing animal deaths, fragmenting and decreasing habitats, preventing wildlife from accessing food and water and isolating populations.
The crossings — bridges or tunnels dedicated to help wildlife cross roads — are one of Nevada’s solutions to reducing animal-involved collisions and preserving some of the animals that call this state home.
Nevada has more than 20 wildlife crossings throughout the state, including under- and overpasses. And out of the 22 bridges in the United States for animals, six are in Nevada, Simpson said.
One of those is the Boulder City Bypass, a $1.6 million project that was built in 2018 with the completion of Interstate 11, Simpson said. The Nevada Department of Transportation incorporated the wildlife bridge into the bypass’s master plan after concerns rose for the bighorn sheep population in the area.
Simpson said there haven’t been any reported collisions with the local bighorn sheep since the bridge was completed.
“We are a desert environment (and) do not have dense populations of wildlife, so we do try to protect and do the right thing for the wildlife we have here, because it’s important to the citizens, and that’s important to us as well,” Simpson said.
A pioneer in wildlife crossings
Crashes involving wild and domestic animals occur each year in Nevada, officials said, causing over $19 million in crash costs and killing an estimated 5,000-plus animals.
Nevada is considered a pioneer in bringing these wildlife crossings to life, Simpson said.
While she was a graduate student at UNR, Simpson helped study the effectiveness of wildlife crossings in Wells, where the first crossing in Nevada was built during the early 2010s. The overpass was constructed to help protect migrating mule deer, said Mike Cox, bighorn sheep and mountain goat staff biologist at Nevada Department of Wildlife.
Simpson and her cohorts “documented a 50% decrease in mortality with each subsequent migration (of deer)” within the first few years of the wildlife crossings being opened, she said.
Cox said a list of priority locations is being created by the Nevada Department of Wildlife and Nevada Department of Transportation. The two also must make an inventory of state connectivity needs, gathering information from other resource management agencies such as the U.S. Forest Service, Simpson said.
The list must be published no later than Dec. 1, in accordance with AB 112.
After these lists are compiled, the agencies will “dive into the data” to see how they can include these crossings into projects where wildlife needs are a concern. They’re also going to be looking at other “fine details” — such as land ownership — to “make a formalized list” of long- and short-term projects.
From there, they will move forward with the process of putting these wildlife crossings into place once they figure out which areas need them.
“We’re going to be working hard over the next calendar year to kind of meet some of the needs that were called out in AB 112, and so I think we’ll have a much better idea and direction for all people involved (and) all agencies to think about,” Simpson said.
Three wildlife bridges are already planned for I-15 as a result of the Brightline West project that will connect Las Vegas and Southern California with a high-speed rail, according to The Associated Press.
Brightline West, alongside California’s Department of Transportation and Department of Wildlife, will work on these bridges on the California side of the border.
Finding the money for these bridges in Nevada was difficult in the past, Simpson said. Animal-vehicle collisions weren’t a top priority for the Nevada Department of Transportation, and so competing for funding against all of the agency’s other projects “has been a challenge.”
One aspect of AB 112 is a Wildlife Crossings Account in the state’s general fund, which would be fueled using grant funding from existing programs like the federal Wildlife Crossings Pilot Program.
This grant program from the U.S. Department of Transportation’s Federal Highway Administration awards selected entities funding for projects “that reduce (wildlife vehicle collisions) and improve habitat connectivity for terrestrial and aquatic species.”
Simpson said the Wildlife Crossings Account will also be used to match any other grant amounts the state receives to help fund future projects.
Nevada appropriated $5 million to the Wildlife Crossings Account, per AB 112. A typical wildlife crossing can cost millions of dollars, but that depends on where it is built and whether or not it is a standalone project, Simpson said.
For example, the Boulder City Bypass that stretches across Interstate 11 was estimated to cost $1.5 million to $2 million because it was wrapped in with the entire I-11 Boulder City Bypass. The two Pequop Summit crossings built over I-80 were estimated at about $10 million because they were not constructed in tandem with another NDOT project, Simpson explained.
A few spots in Southern Nevada are on the minds of Simpson and her team for wildlife crossing additions.
They’ve already submitted a grant application for funds to help build crossings for the desert tortoise populations — listed as threatened by the Endangered Species Act — near Coyote Springs, she said.
Grant approval or not, it won’t be the last wildlife crossing to be established in Southern Nevada.
“The desert tortoise down south has been a really big issue, and we spend a lot of money on the desert tortoise themselves on our projects,” Simpson said. “And so, you know, when we have the ability to put in some of these features, it just makes sense, right?”
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