Above, a vintage photograph of the Snoqualmie Falls Lumber Company in the 1940's followed by a shot from the pilot filmed from the same vantage point, but zoomed-in. The Snoqualmie Falls Lumber Co. (later the Weyerhaeuser Mill) was constructed in 1917 and was the second all-electric mill operation in the country. From 1989 to 1992 it doubled as the Packard Sawmill in Twin Peaks. Just two months after it was filmed for the pilot, the mill was partially dismantled and downsized. Below, and excerpt from Lynch on Lynch about the mill.
I always wondered if the shots from episode 8 on the newscast about the fire at the Packard Mill were taken when the mill was being torn down...? Or perhaps there was a fire at the Weyerhaeuser Mill during the pilot shoot. Who knows? If you know, please fill me in!
Lucky they filmed it when they did! Future scenes of the interior were shot on sets built in L.A.. The remnants of the mill are now listed with the state of Washington as a highly endangered historic property. The building used as the Twin Peaks Sheriff's Department is actually the sawmill's office, located on a ridge just above the mill. (See: The Real Sheriff's Department)
Incidentally, you can see one of the sawmill's smokestacks whiz by in the background as Agent Cooper first drives into Twin Peaks in the pilot, shown below.