The Collaborative International Dictionary of English v.0.48:

Roke \Roke\, n. [See Reek.]
   1. Mist; smoke; damp [Prov. Eng.] [Written also roak,
      rook, and rouk.]
      [1913 Webster]

   2. A vein of ore. [Pov.Eng.] --Halliwell.
      [1913 Webster] Rokeage