I just finished the ground work for my runway. It was recommended to me, by the local soils agency. To go on the MDT Aeronautics Division Website. Airstrip Turf Development. They recommend Sodar Streambank Wheatgrass or Sheep Fescue. MDT is the Montana Division of Transportation, these two seeds are what they use on there turf runways, With good results. I live in north central Idaho and we have similar climate. I went with Sodar streambank Wheatgrass ,after talking with Clearwater Seed they highly recommended it. There office is in Spokane WA. Ph 509 345 3108 Very helpful. They will ship seed to you.
Hope this helps. John