The Middle Fork of the Snoqualmie River has long been thought to have huge potential as a recreational area, less than an hour from Seattle. It’s at the heart of roughly 1.5 million acres of open space in the Mountains to Sound Greenway along I-90. But for decades, the valley was so trashed that even local law enforcement considered it dangerous. That’s changing, now that a new paved road into the area is nearing completion.