So help me figure it out, because I don't think I have a good grip on an answer.
At least in Colorado, from the 1950's through the 1970's, virtually every mountain town had a ski hill. The majority of ski areas in the state generally consisted of a single lift (including rope tows, Poma, T-bar, etc.), less than 1000 feet vert, and under 100 acres. A lot of them operated with less than 150 inches of snow a year.
These have almost all died out, and almost none exist anymore. You can advance very good reasons as to why- increasing insurance, limited appeal compared to larger resorts, most had limited snow, limited vert to attract visitors.
So here is the part I don't get. All of the local hills on the front range have closed. Echo Mountain's rebirth as being Denver's local ski area is now over, all the others closed in the 1980's and before. Colorado Spring's last local hills were closed by 1992- Since WW2 there have been NINE ski areas between Colorado Springs and Divide 30 miles west.
Meanwhile, within an hour (ish) drive from Durango, there are FOUR of these tiny hills operating- Chapman Hill in Durango, Hesperus 10 miles West, Kendall Mountain in Silverton, and Lee's Hill in Ouray. Stretch it out to two hours, and you now have SIX. (adding Cranor Hill in Gunnison and Lake City Wonderland).
These comprise all of the single lift operations in the state, with the only other hill in the same general category being Howelsen in Steamboat.
So, the question I put to you:
What is different about the San Juan area of Colorado that so many of these areas survived, while they died out all over the rest of the state? Its not lack of competition.
Do other regions have anomalies like this?