We live in the Sammamish Valley, carved by the Sammamish Slough. Once a naturally meandering river, the Slough is now channelized and arrow-straight for miles. A couple times a year, it rises in a fruitless attempt to reclaim its natural domain. Fortunately for those living nearby, the planners were thoughtful and they placed mostly sod farms, vegetable farms, soccer fields, and a golf course nearby. There is some housing that encroaches on the Slough, and some industry, but they seem to have well-designed dikes.
Quite a meandering introduction, eh? But you have survived to the point: the valley is scenic. The Red Hook Brewery and the Chateau Ste. Michelle Winery are at the north end of the valley. Somebody decided it would be a good place to run a balloon. The winds are generally northernly (out of the north), so they start at the north end of the valley and drift south. The balloons are surprisingly silent (except for the roar of the propane burners) so that I'm often tempted to start a conversation as the balloonists float over my backyard.