Go to the Elmendorf Air Force Base Website, airspace page, for details: Alaska Airspace Info. Also note that the Delta Temporary MOAs that were periodically issued by NOTAM in years 2010 and earlier have now been made into permanent Delta MOAs and are depicted on the current aeronautical charts, although they are still only used during major military exercises such as Red Flag and Northern Edge.
Operation Red Flag Alaska and Operation Northern Edge are major military exercises that restrict IFR aircraft from large sections of airspace for up to four hours at a time. IFR aircraft cannot be cleared through the Special Use Airspace (SUA) or related airspace while it is active except for emergency aircraft.
This area is established through numerous Restricted Areas, Military Operations Areas (MOAs) and Air Traffic Control Assigned Airspace (ATCAA). As you may know, MOAs can only be established below flight level 180, however at flight level 180 and above there is an equivalent type of airspace known as Air Traffic Control Assigned Airspace (ATCAA). ATCAA areas are not depicted on any standard aeronautical chart, however I did find a map of MOA and ATCAA areas on the Anchorage ARTCC website. In most cases an ATCAA area will cover the same area as an MOA below it and carry the same name. For example, Eielson ATCAA is above Eielson MOA. This map was created in February 2008, so it may or may not be current. Do not use it for anything critical. Map of MOA and ATCAA Areas in Anchorage ARTCC Airspace
Although there are some other areas involved, the main area of focus, using true direction, includes all Special Use Airspace (SUA) and related airspace in the area (approximately) from Fairbanks (FAI) to Fort Yukon (FYU) to 100 NM east of Forth Yukon (FYU) to Boundary (BYA) to 40 NM northwest of Gulkana (GKN) to 35 NM east northeast of Talkeetna (TKA) back to Fairbanks (FAI). When looking at all airspaces combined, this restricts all non-emergency civil IFR traffic virtually throughout that entire area at all altitudes from Flight Level 600 and below. The floor varies from one area to the next, but in most cases extends below IFR minimum altitudes effectively blocking all IFR traffic at all altitudes.
The routes between Northway (ORT) and Fairbanks (FAI) or Northway (ORT) and Fort Yukon (FYU) would have the greatest impact. Reroutes will likely be impractical except for jet aircraft because of the distance involved. Aircraft would have to remain south of all Fox and Eielson MOAs and ATCAAs until they clear the west side of those areas, then turn north toward FAI. There is an exception for aircraft between Flight Levels 320 and 350 south of 63 degrees north latitude. This could offer a slight short cut for some folks but not likely to work for aircraft landing FAI because after clearing the airspace you would have to loose 32,000 or more feet in about 100 NM. This essentially means an IFR flight from Northway (ORT) to Fairbanks (FAI) would have to fly from Northway (ORT) to Talkeetna (TKA) to Fairbanks (FAI) or something similar. For a slower aircraft it would probably be less of a delay to wait on the ground until the airspaces opens up again since it is only active for four hours at a time or less.
VFR flights will have little impact since there is a low level VFR corridor along the highway(s). VFR flight through an active MOA is not prohibited although it may not be advisable either. Make sure you are familiar with the Special Use Airspace Information Service (SUAIS) and contact Eielson Range Control on 125.3 if you fly through the area VFR. Check out the SUAIS Brochure (pdf).