The T'Plana-Hath landing in Bozeman.
The T'Plana-Hath was a Vulcan vessel in service during the mid-21st century.
On the morning of April 5th, 2063, it was passing through the outskirts of the Sol system, when it detected Dr. Zefram Cochrane's warp signature during a test flight of the Phoenix from the vicinity of Earth, a planet which the Vulcan High Command had been monitoring for decades. As per Vulcan first contact protocols, they decided to land on Earth, to meet the person who flew the first warp ship of their world. They landed in Bozeman, Montana. (Star Trek: First Contact, ENT: "Desert Crossing", "Carbon Creek")
The senior of its three-person crew exited the vehicle first, and offered the Vulcan salute, and "Live long, and prosper." Dr. Cochrane tried and failed to perform the same hand gesture, so he shook the Vulcan's hand, and said thanks. The Vulcans and Dr. Cochrane then went into the local establishment for beverages, and a presentation of the local music. (Star Trek: First Contact)
In the mirror universe, first contact proceeded very differently, as Cochrane shot and killed the T'Plana-Hath's captain. The assembled humans similarly executed the rest of the Vulcan crew, stormed the ship and raided it for its technology. (ENT: "In a Mirror, Darkly")
It was named for T'Plana-Hath, the matron of Vulcan philosophy. (Star Trek IV: The Voyage Home)