Its swampI think a better synonym is plain (extensive area of flat land). A swamp is a wet damp place, prairies or plain are not necessarily wet.
What is a synonym for quagmire?
A quagmire could be a bog, swamp, marsh.
Or metaphorically, a trap, quandary, entanglement, or
predicament.
Adjectives could include mired, caught (as in a quagmire),
stuck, or trapped.