The Tesla Semi isn’t due to go into production until 2019, but there are already prototypes of the electric truck on the road in California. A recent report reveals the Semi has moved beyond brief excursions around the company’s Bay Area factory and has ventured onto the highway — and that this foreshadows its first regular route for the truck’s first official customer.

As Electrek reports Wednesday, that customer would be Tesla itself. The truck was spotted on a highway outside Sacramento, which is roughly midway between the Tesla assembly facility north of San Jose and the Gigafactory located just east of Reno, Nevada.

Tesla executive Jerome Guillen said last year that the trucks would be used to carry materials between the two sites, though Tesla founder Elon Musk has since suggested The Boring Company could eventually build a hyperloop. The Tesla Semi seems like a smart, short-term bet, at the very least.

The 258-mile journey between the two points would also be an ideal test of the Semi’s range, which Tesla founder Elon Musk claimed was about 500 miles at the unveiling in November. A round trip journey between the two would push the Semi to its stated limits, and perhaps slightly beyond, though in all likelihood the trucks would recharge at either location before making a return trip.

As Electrek notes, the only time we have actually seen the Tesla Semi with its trailer attached was at the November debut. A truck with a fully loaded trailer inherently can’t have the same kind of range as the vehicle alone, so the more revealing demonstrations will come when the prototypes take to the road with cargo.

Ever the optimist about his own creations, Musk tweeted last week that he is hopeful the truck can beat its previously announced specifications without an increase in the price, which is $150,000 for the 300-mile version and $180,000 for the 500-mile version.

While it’s always worth treating what is fundamentally a hype line with caution, Musk’s background as an engineer makes this a more intriguing statement than if he were a strictly sales-focused CEO. Depending on how the initial freight runs between the Tesla facilities go, to say nothing of the planned start of production in 2019, it’s possible that Musk’s company will eventually turn into a trucking company with a small car-making component.