Use multiple GPSes:  I carried two GPSes – the second as backup and also, since all individual tracks have error, to allow track averaging. And if the two GPS tracks differed significantly – in poor reception conditions a track can suddenly shift, the unshifted one would indicate the “correct” track. When I started, handheld Garmin GPSes (GPSMAP 60) had just come onto the market – without that availability I would not have attempted this mapping project.  Over the years, newer Garmin units were used. (Due to the brush encountered, I had to buy a special clip to hold the GPS securely, since the need to mark waypoints necessitated outside access to one GPS – and had to replace my first GPS due to brush eventually trashing its buttons.)

Save clues on GPS and recorder:  in the absence of tread, one must look for other clues. Examples of “definite” trail indicators are rockwork and sawed trunks. Also useful are old flags and cut branches.  Sometime “tread” seems to be found but can be questionable – deer and other animal paths abound. I carried an Olympus voice recorder and if not on obvious tread, upon finding a clue would put a marker into my GPS and record the type and quality of that evidence – or if the apparent tread became questionable would mark+note that. After the hike, I’d save the tracks and waypoints and transcribe recorder notes – when the route of the trail was questionable I could piece together the “good” points.  Most trails were traversed at least twice, often as in-and-out dayhikes.

Have a preliminary guess:  when available, I put a georeferenced trail route from a map in Jeffrey Schaffer’s “Hiking the Big Sur Country” (1988) into my GPSes. While I also had track and camp info from the USFS that was often found to be misleading and unhelpful, as was true for the Mt.  Manuel Trail). Unfortunately even Schaffer’s routes had enough error (see box below) that they were often not useful for re-finding a trail when tread was lost.  Another example – when I could not follow the faint tread after it went into a large area covered with blowdown trees, I luckily found an old satellite image showing a switchback emerging from that area – so that point was put into the GPS as a “go-to” for my next attempt.

Jeffery Schaffer
and his mapping

Jeff “Mad Dog” Schaffer, whom I twice met in person, worked before GPS was available, becoming familiar with mapping techniques during his geological training. He used compass and step-counting together with topo maps to produce high-quality trail maps.  He emphasized to me that the accuracy of his trail mapping was limited by the accuracy of the topo maps he used – if actual terrain differs from that, a lat/lon obtained from a georeferenced map will not be accurate, and back then, terrain data was not of today’s accuracy. So the changes of direction, twists and turns, of his lines were more significant than their exact location. (BTW the same is true for my mapping, hence Big Sur Trailmap trails are sequences of short straight lines rather than a smoothed line.)

Jeff’s initial fame came from mapping the Pacific Coast Trail, authoring several trailblazing guidebooks published by Wilderness Press in the early 1970s.  In the late 1980’s he mapped the Ventana Wilderness (and Big Sur State Parks, but not the Silver Peak Wilderness) and published them in Wilderness Press’s “Hiking the Big Sur County” – the first reliable maps of the Ventana Wilderness trail system (though with some omissions, the Black Cone Trail for example).  How this came about (he did not initially want to do the mapping) and his resulting mixed feelings (for one, he disliked the photo used for the cover) makes an interesting story – if we should meet, you can ask.