Is Three Tree City legal in Standard, Modern, and Commander?

Three Tree City is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

What type of card is Three Tree City?

Three Tree City is a Legendary Land. Its oracle text reads: "As Three Tree City enters, choose a creature type. {T}: Add {C}. {2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type."