Late last week, Elon Musk made a low-key but important announcement via twitter. Tesla has just completed the coast-to-coast Supercharger network needed to allow the Tesla Model S to make a cross-country drive. It’s the first network of its kind in the U.S., and an important step in Tesla’s planned dominance of the American automotive market.

According to Musk, some 80% of Americans are “covered” by the Supercharger network, and with the completion of the interior corridor, Model S drivers can now drive from one coast to the other and back, for free, using the fast-charging system. Of course the Tesla Supercharger network doesn’t stop there, as there are plans to install many dozens more free filling stations, until the entire country is covered.

Tesla Supercharger network now energized from New York to LA, both coast + Texas! Approx 80% of US population covered. — Elon Musk (@elonmusk) January 26, 2014

The network should be firmly established by the time the Tesla Model E comes to market in 2017, and the proprietary charging technology will give Tesla a huge advantage over competitors whose cars rely on home or public charging stations. Buying a Tesla doesn’t just mean buying a cutting edge electric car; it means access to free fuel forever, or at least until Tesla changes its business plan.

For now though, Tesla-owning Americans can now enjoy a classic American road trip without paying a single penny for fuel, a remarkable advancement in just a short amount of time. Now about those battery swapping stations…