Sentence:  Along Wappinger Creek in Dutchess County , past the white church at Fishkill , past Verplanck 's Point on the east bank of the Hudson , to the white salt <WSD>crusted</WSD> roads of the Long Island Rockaways there was a watching and an activity of preparing for something explosive to happen . 
Meaning of the word marked with <WSD> tags:  having a hardened crust as a covering