There's been some talk about the ride from Ash Fork to Kingman on route 66, but one's a Flagstaff rider and another's in the central deserts (that'd be me). And it was too durn hot so my ride quit just your side of Seligman.
I recommend you go swimming in the Colorado River and ask again this fall!
I grew up in Bullhead City and spent a lot of time in the hills around Oatman exploring mines and hiking. I always thought that having a sweet, durable mountain bike to explore through there would be fun! Of course I'm talking about the golden valley area going towards BHC. Looks to be a lot of trails around there. Hope you find someone to ride with you. If I was still in the area I'd love to go exploring with you through there!