I took a "shortcut" at Idaho City to get to Horseshoe Bend. It was 38 miles of washboard gravel with lots of curves and fairly steep grades and lots of dust. This photo is at Placerville. I ended up on the course and had to get to Horseshoe Bend before they closed the road at 1 pm. I've never been so dirty, except maybe after spending a week in the Black Rock desert dust...it was a trip riding the big loaded-up Connie with street tires on that road. Info on the rally is at idahorally.com
I've ridden on gravel but this was challenging because it was deep gravel in spots and the dust was so thick when cars passed me it was hard to see - plus it was about 95 degrees. It was a blast I almost only lost it once. I thought it was interesting that I kept seeing those rally cars on part of the road and then found out this a big race for them. This picture is of a local car - there were lots of them with professional sponsorship logos too. It's the racing where they have a driver and a navigator - that you see on TV every so often.
I have to say that Concours is one tough bike - it rode fine in the dust and vibration from the washboards and then 160 miles up here to La Grande at 75 mph and temps of just about 100 (98 in Ontario Oregon when I passed through town).