The comment on counting the number of bends reminds me of years past and another type of navigation. When I went through flight training decades back (way before GPS) I flew a few low level navigation flights in Utah/Nevada. In dead reckoning you turn based on time if you have no other input; there was so much to see and stay found in that rugged country that DR was not an issue; I had checkpoints that were used simply as confirmation that I was near my intended track and time. At the end was a "target" which had an intended overhead time. On one leg I counted ridge-lines and simply turned down the middle of the valley. Another trainee took the "turn-on-time" option and turned down the wrong valley - doh! That happened to be my check-ride and I overflew the target within seconds of my intended time.

But that's DR with a view from 500 ft up doing 300 KIAS, not 6 ft doing 2 mph -- slight difference. Still, the same principle applies, take a heading and speed, and with no other input, turn on time. At some point though, you need to get a fix and find out for sure where you are located.

The real question when doing back-country navigation is, are you seeing the sights while navigating, or are you navigating while seeing the sights. Which comes first? Do you find yourself after getting lost or do you simply stay found? Trust me, the guy that flew down the wrong valley stayed lost.