South Fork Owhyee
Have done the South Fork, from El Paso Pipeline to 45 Ranch in 14' paddleraft. Very scenic, couple of old ruined homesteads, several decent campsites, including where Claude Dallas killed the Fish & Wildlife officer. Lots of busy class II and II+ rapids. There's a rock weir right above 45 Ranch; looked runnable maybe but we portaged. Saw the biggest, fattest raccoon ever, stalking a family of gosling (till we came along and spoiled his plans.) Lots of rattlesnakes.
You can launch up higher at the YP Ranch, with landowner permission (contact Elko BLM for phone info). Roads are terrible when wet. Road into pipeline launch site 4WD. Not many landmarks for navigation - take a GPS and BLM 1:100,000 map.