Thanks Jerseyman,
That goes along with John said that day. He pointed out that the reason the road was south of 563 was they did not like hills at all in those days. In fact, he said the old bridge remnamts may still be visible just south of the Harrisville ruins where there is a small island in the middle of the stream.
Another interesting thing he pointed out: it was not uncommon for the roads to become very saturated with water because of the travel in this low ground, so they would just move the road over to the next dry section, be it 10 feet or 40 feet or whatever. He said you can still see that in some areas, where there are 3 roads in a row. I have seen this before, but never made the connection.