Tom Ferrell posted the route:
I set what I believe to be the fastest known time on the Mount Defiance trail yesterday afternoon (April 21 ). The trail is approximately 11.5 miles, with 5,000 ft of elevation gain and loss. I started and ended at the trailhead sign at the west end of the parking lot at the Starvation Creek exit off I-84. I ran the Mount Defiance trail the entire way (not the Starvation Ridge route). I took the right fork at the intersection connecting to Warren Lake at approximately 5 miles, and took the left fork about a quarter mile later, where there are now temporary yellow signs indicating easier route versus harder. I took the harder route (yellow markings), which then crosses the road twice. After crossing the road the second time, there is a short section in the trees, and you emerge right at a guy wire for the radio tower. I ran around the east side of the fenced tower, and ended at the propane tank, where there is a view of Mt Hood on a clear day. I took the same route up and down. I ran alone (though I saw a couple people on the trail) and carried my own water.
The link to my Garmin information is below, and you can zoom in pretty clearly on the route that was taken, as well as the starting and end points (granting the standard error of GPS when you zoom in). I ran up in 1:19:31 and had a total time of 2:12:48. The total elevation gain and loss was very close to 5,000ft. I never stopped the watch during the run, only hit the lap button at the top turnaround point. My autolap feature is set to 0.95mi for trail running as I find that to be the closest to accurate for 1.0 mi as I always lose some reception in the trees. The total distance listed is 10.84 miles, though I'm still not completely sure how long the trail truly is. I've seen it listed anywhere from 5-6 miles each way. I think ~5.75 miles is closest to accurate. With the combination of tree and cloud cover, if my watch measured 5% short, that would be right at 11.5 total miles.
Christof Teuacher ran a Quintuple Mt. Defiance: www.teuscher.ch/aagaa/report-quintuple-mt-defiance-in-24h ...
and 3 years later 6 out & back laps in 22h39m: http://www.christofteuscher.com/aagaa/report-sextuple-mt-defiance-in-22h39min/