Fifty miles!
You can correct the trail in Map Maker -- click in the bottom right corner where it says Edit in Google Map Maker, then Edit -> Select a line, then select the trail where you want to edit, and then select the trail on the left. The segment of the trail will have details you can edit, I think that particular segment says paved or something like that, you could edit attributes, there is Access, and Bike suitability.
I had no idea you could do that! Now I have to figure out how you delete that segment...
The race lists a 60 mile cap on biking so 50 seemed like a good target for a Sunday morning. I felt I could go farther; granted the terrain was super easy. Given the conditions, I think your Poto run yesterday was harder, with heat and hills.