The North Face Endurance Challenge 50 mile run San Francisco, CA

Situated in the visually stunning Marin Headlands just north of the city, The North Face® Endurance Challenge Championship course has surprised runners with both its scenery and amount of elevation change. Participants are encouraged to train for repeated uphills and downhills of several hundred feet at a time.
http://www2.thenorthface.com/endurancechallenge/races/2009/ca/index.html
A majority of the course covers run-able fire road (very little technical single track) overlooking the Pacific Ocean with occasional glimpses of the Golden Gate Bridge.