(Arid Gorge isn't a spell.)
Arid Gorge enters the battlefield tapped.
, : Scry 2.
, Pay 1 life, Sacrifice Arid Gorge: Search your library for a Mountain or Plains card and put it onto the battlefield, then shuffle your library.
, 
: Scry 2., Pay 1 life, Sacrifice Arid Gorge: Search your library for a Mountain or Plains card and put it onto the battlefield, then shuffle your library.
