During the Reagan era there was a move to privatize everything including the USGS map publishing group. At one point the USGS was instructed to stop printing any new maps, they would let private industry take over. Many rural parts of the country were still using 15 minute quads from the 1920's. There was some resistance to the USGS proposal so the government agree to update all the US to 7.5 minute quads. Soon thereafter a large volume of new 7.5 minute provisional were produced. They were based on fairly good topography that I believe were obtained from satellites but the field work was provisional, thus the maps had hand entered notes and temporary bench marks in place of neat lettering. I believe during this period various mountains "grew" or "fell" on the maps. The 100 highest list also changed, so the "four pack" in the Eustis area turned into the "six pack" and middle Abraham and east Horn fell off the list. The 4 K committee (basically Gene Daniels) said enough with revising the lists and made one last revision based on the 1987 provisional quads. I believe that the ongoing plan was that if the elevations changed again due to later map revision that the list would be frozen like the ADK lists. There was one or two year grace period. When I did the traditional labor day hike to the four pack with AMC, we stopped by Kennebago divide as Gene mentioned that it would soon count. I still haven't gotten back up there to add in Snow but I was done with the list before the new list kicked in.
The other driver of updating the maps all over the US was the attempt to locate a new nuclear waste repository. There were many new geological maps issued by the government that were produced during the effort.
As an aside, when I first started the 100 highest list many of the 7.5 minute provisional for the more remote summits (like the 4 pack) were not yet available. It was the early age of the internet and my brother read a post on a use group that if someone bought $500 worth of USGS maps, they became a map dealer and got a 50% discount. In order to order the maps the USGS published two books, one was an index of the new map quads names and the other one was an index to the published maps. On a whim I included several maps that were named but listed as not published on the order. A few weeks later I got my part of the order and I ended up with the new quads for many of the remote 100 highest. For about a year folks I ran into in the then much 100 highest community kept asking me where I got those new maps. The year of the first VFTT gathering in Eustis, I was quite surprised to see that the general store had started stocking the new maps about 2 years after I had gotten mine.
