Iowa Hill Challenge is a 46.5 mile loop trail located near Colfax, CA. The trail is rated as moderate and primarily used for road biking.
The GPS on the app (and according to the map on this page) for this trail takes you to a residential neighborhood in Colfax. We couldn't find any indication of a trailhead. Very disappointing, as we drove 30 minutes to get there, and couldn't go for a ride because there doesn't seem to be any other road trails in Colfax, according to the app. If there is a trailhead for this, please get it corrected on the app. Or if anyone knows how to find the trailhead, please reply to this review. Thanks!