Waymo, the Google self-driving car project that officially became a company in December, is taking its Chrysler Pacifica Hybrid minivans out of the mild environment of Silicon Valley and putting it in more challenging conditions.
Waymo CEO John Krafcik tweeted Monday morning a picture of the self-driving minivans in the snow in South Lake Tahoe, Calif. Testing took place on public roads around Lake Tahoe, on the California side.
In a tweet posted Monday afternoon, the company said it was collecting snow data to train its self-driving software.
Snow, slush, and freezing rain are challenging for self-driving cars because the wintry weather condition can obscure roads and lane markings as well as muck up sensors used by these vehicles to see the world around it.
In 2012, when the company was still a “project” under Google’s moonshot factory X, it conducted a similar tests on public roads in Tahoe with its modified Lexus vehicles, according to the company.
Last year, Ford showed off its winter testing, which was conducted in Michigan. Both Waymo’s and Ford’s self-driving test vehicles use LiDAR, a light detection and ranging radar that emits short pulses of laser light to allow the vehicle to create a real-time, high-definition 3D image of what’s around it. LiDAR senses nearby objects and uses cues to determine the best driving path.
Get Data Sheet, Fortune’s technology newsletter.
Waymo is adding 100 of these self-driving minivans to its fleet, as part of a collaboration announced in May with Fiat Chrysler Automobiles (FCAU)—the first time the tech company has worked directly with an automaker to create its autonomous vehicles.
Waymo took the wraps off its autonomous minivans in December. The following month ahead of the North American International Auto Show kicked off in Detroit, Krafcik provided a deeper look into the company’s business model, the technology inside the vehicle, and its timeline for testing on public roads.