I'm planning a week of riding in July in the Black Hills--our party will be one DR, one 650GS, one KLR. I have the stock tank (3.4 gal) on the DR and I'm wondering whether I need to buy an IMS (4.9) tank and/or figure out how to carry some extra fuel. I already notified the KLR rider I'd be siphoning out of his tank. We plan to ride mostly forest service roads and easier trails, and I think we'll be primitive camping most or all of the time. We're all riding in from different locales on the bikes, no other vehicles. I've found some good routes to ride on ADVRider threads, so maybe when I start comparing the trip reports to the USFS maps I'll get a better idea of where the closest towns are. In the meantime, does anyone who's been there have advice on availability of gas, or how much range is necessary to not be worrying about fuel? I appreciate any feedback.