To qualify for this cache, you have to find thirteen caches, each of which are at least one mile from the nearest legal access off a drivable road (one mile via the shortest legal walking route, as the trail goes, not as the crow flies). If your walk closely parallels a limited-access highway, we're not going to assume that you pulled over on the shoulder and then hopped the fence to grab that cache halfway between exits, so that cache might qualify if it's one-mile from the nearest point at which you can actually start walking. On the other hand, your nice walk in a county park might not qualify if there are multiple unofficial trailheads: you might not ever be more than one mile via the trail from some entrance point off a neighborhood street. Caches you own and maintain count as "finds" for meeting this challenge - as long as they are a mile or more walk from the road access - because, obviously, you had to take that walk at least once when you placed them.
But wait, there's something else - you have to find them (or have placed them) on separate days, so there's no advantage in going for a twentysix mile hike and finding dozens of caches somewhere along the trail. If you want, you may revisit the same park and trail on separate days, each time going just a little further to find another qualifying cache. You can go as far as you want or need, but you don't get any "extra points" for going further. So take it easy on yourself ... a little exercise every day is better than one marathon session.
The days you walk don't have to be consecutive.
It's probably easier to walk a mile each way than to prove that you actually walked it to someone who didn't witness you doing it. If you're caching in Bay Area parks, you may not need to provide any special proof as to the cache being a mile in from the nearest road, since I may already be familiar with those trails and those caches. But please don't count on my memory - or yours - of the distances involved. Be ready if asked to link to the official trail map provided by the agency which administers the park, or to a GoogleEarth kmz, or to an EveryTrail listing, or to whatever other listing source can confirm to everyone's satisfaction that you've met the challenge.
Intermediate/final - physical - stages of Puzzle, Multi, and Letterbox caches qualify if you can prove that they meet the requirements of having to walk one mile or more away from the road. (I know that can be proven for at least a few, without compromising their actual solutions.) This cache counts.
It's just a little over one mile from the nearest trailhead at the San Juan Bautista end of the De Anza / Old Stagecoach Trail. No bushwhacking. The cache is black, tucked in natural camo, reachable from the edge of the trail.
When logging your Challenge find here, please list the qualifying cache names, GC#, with dates found. Feel free to add any helpful extra info. Happy trails to you!