Steam Vents is a rare Land — Island Mountain card from Lorwyn Eclipsed Promos (PECL), collector number 267p. Current market price: $12.67 (foil $13.07), TCGplayer market prices via Scryfall.
({T}: Add {U} or {R}.) As this land enters, you may pay 2 life. If you don't, it enters tapped.