The Lark Hill Dusk to Dawn on Saturday, 3 March 2018 is a 50km & 100km ultra marathon and 25km run on an approximately 3km limestone loop course at Port Kennedy in Western Australia.
25km runners run 8 laps; 50km runners run 17 laps; 100km run 34 laps. Because the event is run at night, it is recommended that runners use a headlamp. Both events start at 7pm and there is a 13 hour cut-off, i.e. at 8am the following morning.