Sometime early in the 1900's, everything began to change. The building of a road from Altadena to the top, made it easier to access Mt. Wilson via automobile. Additionally, Sierra Madre outlawed pack animals and stables within city limits. At that point in time, according to an interesting article I found on the Sierra Madre Historical Preservation Society Website, "the days of a full service facility at the trailhead were coming to a close."
The Trail Inn was able to stay in business until 1948, and the barn, stable, and other structures were not removed until 1961. Luckily, Lizzie's Trail Inn and The Richardson House were saved, so we can all visit a bit of that time in our history.