The Collaborative International Dictionary of English v.0.48:

canoncito \ca[~n]`on*ci"to\, n. [Amer. Sp. dim. See ca[~n]on.]
   [Southwestern U. S.]
   1. A small ca[~n]on.
      [Webster 1913 Suppl.]

   2. A narrow passage or lane through chaparral or a forest.
      [Webster 1913 Suppl.]