Johnie, about 10-15 minutes depending on the conditions wheather, track surface and the like. Its just had a dozer skim the top of the track so its was realitvely fast going on sunday. The downhill run is just as good but a little harder to capture on a camera.
Years back, me and a friend rode the track aftervsome serious rain. We got up the south side (in pic) no probs but the north side had the built up parts in the gullys washed out. The first one we came up to was'nt too much of a drama, we managed to ride across it. The next one was a bit worse and we had to manhandle the bikes across the gap. Then it turned to s**t for us! Believing that we had seen the worst parts we decided to press on. The next washouts saw me standing in the holes holding the front wheel of my mates bike above my head while he had to clamber his way across and grab it off me while I latched on to the back wheel and passed the thing over to him. Luckily we had light bikes. IT 200s and Phills was a YZ 125 with an IT 200 motor in it. What takes maybe 3/4 hour on average to ride, this day took us nearly 3/4 of the day.
Its not named the "Devil's Staircase" for nothing. The whole area is just chocka with similar tracks of the like. Awesome place.