TBH, not my favorite day of riding. First, there's one business between Sunnyside and Mattawa (there's a convenience store where Hwy241 hits 24). Otherwise it's dry pastureland or, where there's irrigation, grapes and apples. The day starts with a 10mi (gentle) climb on Hwy 241 out of town. By the time you get to the top (the divider between the Yakima and Columbia valleys) there's a stiff headwind. It took us about 90 minutes to cover 10 miles. I didn't think we'd ever get to the top. Then there is a much needed 5 miles downhill until you hit Hwy 24. Although 241 started with ok shoulders, they deteriorated to minimal near the end which wasn't particularly comfortable with the truck traffic Hwy 24 starts with several more miles of uphill at about 4%, but at least there's a great shoulder. Once you get to the top of that hill, it's all downhill to the Vernita Bridge over the Columbia. The shoulder continued good, but truck traffic increased too. After a packed lunch at the (very nice) rest area at the bridge, we managed to get across during a break in traffic. The bridge has zero shoulder/no sidewalk and heavy truck traffic. We got lucky with the break in traffic or the bridge would have been really unpleasant. Unfortunately, we had to continue about another 5 miles on Hwy 24. After about a mile, the shoulder went to zero. Slightly more traffic and this would go on my Do Not Ride list. Unfortunately it's hard to avoid. At 5 miles we got to turn off on much quieter country roads that after a little more climbing took us to Mattawa and a much needed break at a Subway. After Mattawa, we dropped back to Hwy 24, but now with a better shoulder (and yet more traffic). I was happy to get off the Hwy again as we neared our accommodation. In addition to some really questionable roads, what really downgraded the ride was air quality. Smoke from fires in the Cascades has pushed the AQI into Very Unhealthy and visibility down to about a mile. The smoke is so heavy even the big open sky views and seeing the geology of the Beverly water gap on the Columbia are getting lost in the haze. The high temp is only 82, so at least we got lucky there. Overall though, it was a challenging ride with little reward.