Riveteers Overlook is a common Land card from Modern Horizons 3 Commander (M3C), collector number 369. Current market price: $0.35, TCGplayer market prices via Scryfall.
When this land enters, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.