As far as I can tell the cave in at the Tunnel was the same as the Trout Creek wash out story, they were operating along both well after both events supposedly happened. Both stories seemed to come in decades later and I am not sure why.
The real reason was the line was losing money and had no realistic hope of changing, so 3 events happened at the same time, Tunnel and south of Garos closure, and of course Boreas Pass. The kept the St Elmo BV section running but not that willingly.
The only one changed was Boreas Pass and not willingly. They certainly took everything of value out as part of the process. All, well nearly all of the contents of the Como hotel were removed, two car loads, the Roundhouse they intended to lock up, Section House was already empty, the Tenements were boarded up, I think the lower tank had its pump removed, basically anything they could was moved to where it could be reused. The Dispatchers House by this time was described as a Club House. You just get the feel that this was a tail end of a long process.
Part of the sales pitch for Breckenridge was an improved service, daily, they did not believe it it seems and they had good cause.
Going back to the earlier comment, the Wooden Boarding House at Alpine dates from 1906 so was not used very long, prior to that the Engine Shed was partitioned, there was a liability claim for a guy working at the Eating House who fell into the turntable pit.
There was an advert for a
good girl to work up there, $25 a month, presumably in the Section House/Kitchen.