I am not sure of the exit number @ 59. I may be wrong but I do not think their is a boat ramp at 59. However, I have made a trip the opposite way from 1960 to 59 and beyond about three miles. It is a neat little trip but I suggest bringing a GPS. The water gets shallow at part but since you are in a jet it's nothing to worry about. Another neat trip is running from 1960 up the East fork. The East fork was a lot easier to navigate.
Go to to my profile and look at post # 23 threw 27 and you can read about my trip mention above.
Or search this Title "Texas Divisions / South / Re: San Jacinto, West Fork??"
Jason H.