In what is being hailed as the first cross-country delivery by an automated semi truck, Plus.ai brought butter from California to Pennsylvania—no driver required.

The Cupertino-based (of course) company took three days to tow the 40,000-pound shipment from Tulare, California, to Quakertown, Pennsylvania—which is a 2,800-mile trip.

The technology behind the wheel included “multimodal sensor fusion, deep learning visual algorithms, and simultaneous location and mapping (SLAM) technologies,” according to the press release. That puts the technology at what is known as automation level four, where a human driver stands by for situations that are too difficult or too dangerous for the vehicle to handle itself. Level five requires no human interaction whatsoever, so while it’s a landmark delivery, it’s not exactly the last triumph for big-truck deliveries.

According to Plus.ai, the vehicle “drove primarily in autonomous mode” as it encountered various traffic and weather conditions including mountainous roads, long tunnels, road construction, rain and snow. How much the supervising driver had to do is not quite clear.

Land O’ Lakes, who delivered the butter, said this is another point of validation for the technology that could “reshape commercial shipping.”

“Self-driving and other emerging transportation technologies stand to completely reshape commercial shipping, so we are thrilled to collaborate with technology leaders like Plus.ai to pilot autonomous trucks for our shipping needs,” said Yone Dewberry, Land O’Lakes’ chief supply chain officer in a press release. “End of the year is a very busy time for us. To be able to address this peak demand with a fuel- and cost-effective freight transport solution will be tremendously valuable to our business.”

So if you’re in Pennsylvania, you might just be making holiday cookies with some ultra-fresh robo-butter this year.

Plus.ai is also working in China and across the country. Notably, the company inked a deal with the Minnesota Department of Transportation to test the trucks in wintry conditions.

It should be noted; this is not the first cross-country trip for a level four vehicle. Self-driving truck startup Embark traveled from Los Angeles to Jacksonville, Florida, in February of last year.