24-Apr-2007 -- The field with the confluence was posted, as noted by previous visitors, but this time the fence surrounded it completely, so it seems like the only way to make future visits would be by finding the owner and getting permission.
Instead of following Gordon Spence's excellent narrative, and arrive via Interstate 90, I wanted to avoid the central parts of Houston: My starting point was near I10, due west of the city, so I took the Sam Houston Beltaway around the city to the north, then followed a set of smaller roads which passed across Lake Houston, until I arrived north of the confluence area.
I did drive down 6042, and found an open gate at the end, although with a sign on it. I left my car there and started walking. I soon got to the field that contains the confluence, at this time of the year it was both very muddy, and seemed to be completely fenced in, with [NO TRESPASSING] signs at regular intervals.
At this point Gordon sneaked around and entered the field from the opposite side, but I decided that 370 m away would have to be sufficient, since I didn't have time to go looking for the owner to ask for permission to walk onto his field.