The Lost River

The Lost River enters the battlefield tapped. The Lost River does not untap during your untap phase. This land can only be untaped once per turn. If a nontoken creature would die on your turn, you may exile instead. Then if you have exiled 5 or more cards this way, untap The Lost River. {T}:{B}{B}{B}{flavor}“Terrain scans indicate this biome contains unusually high concentrations of organic and fossilized remains.” - PDA