Leaving town of Grand Coulee heading north on HWY 155 towards town of Coulee Dam the speed limit goes from 30 to 40 mph for about 1 mile. Then drops back to 30 just before the tourist parking / scenic overlook area above the top of the dam–where the local "finest" hang out. The "reduced speed-30" sign is arguably close to the limit sign. Bonus: They are able to also catch speeders coming up the hill–2 lanes–so watch your speed when passing coming up the hill. They use the "Model Dam" at the scenic overlook as concealment depending on which way they want to catch the speeders.