If you drive south from Sugar Land, down US 59, it crosses the Brazo River. There used to be a U-turn on the north side of the of the river, that went under the freeway, close to the river.
Before the area was developed, the bridge was remote, with easy access to the river. It allowed a quick way to dump bodies unseen, under the bridge, and make a quick escape back to Houston. They barely had to slow down.
The U-turn was closed in 1995 to deter the body dumping. But the freeway has been remade and it seems from Google maps the turnaround is open again. I guess I should check it out to see if there is still access to the river.
Update, it is open for business: http://goo.gl/maps/XEZWi