Source : Webster's Revised Unabridged Dictionary (1913)

Northmost \North"most`\ (-m[=o]st), a. [AS. nor[eth]mest.
   Cf.{Aftermost}.]
   Lying farthest north; northernmost.

         Northmost part of the coast of Mozambique. --De Foe.

Source : WordNet®

northmost
     adj : situated farthest north; "Alaska is our northernmost state"
           [syn: {northernmost}]