Numerous other ski areas around the country which have installed high-speed quad or six-pack lifts over the years have easily fit the installation into the normal 6-month offseason (late April to late October).
I don't have any inside scoop, but I've heard people grouse about late construction start times in the Pac. NW (compared to those hard working people in the Rockies, Alps, etc.) for years. A few things that may contribute:
Maritime snowpack is deeper/denser so takes longer to melt.
Forest Service and BLM rules disfavor large amounts of ground disruption during rainy spring months when opportunity for erosion is greater than it might be in a drier climate.
Most PNW mountain resorts are on public land, so animal protection laws are enforced even more heartily, which comes into play during spring "birthing" months when elk calve, raptor birds nest, etc. and noise (dynamiting, etc.) has to be kept to a minimum to avoid stressing the animal moms.
It might have been part of it.
