The goosenecks of the San Juan River are a series of river switchbacks, called goosenecks, 1200 feet below the flat surface of the mesa above, where the state of Utah has established Goosenecks State Park.   The views are very grand, unforgettable.

Camping is$10/night and there are semi-developed spots with picnic tables or you can drive out the bumpy but easily negotiated dirt road and camp as close as you want to the edge of the precipice.  Any size rig can fit; there are numerous large turn-around areas. 

I got between one and two bars of Verizon. 

Tents *not* advised.  It can (and did) get intermittently very very windy.