Here are the probable dates for the two field courses:
400b [3 + 3]: Course begins IN SEATTLE/JHN on Sunday or Monday, June 17, right after Commencement. Arrives in Montana ~June 23 and returns to Seattle ~ July 13. Note: One week of GIS in Seattle, then three weeks field in Montana, then more GIS here.
400a [six-week course]: leaves Seattle for Montana on June 30, returns to Seattle on Saturday, August 10.