Posting this nearly a year later to motivate others to take a shot.
After just missing a sub six hour loop a couple weeks ago on a hot smoky day, I am came back for redemption. The weather was cooler, and I decided not to use my poles. I elected to run the loop from the Browder Ridge trailhead clockwise. That puts the paved 2 mile section at the beginning while I was fresh and could take full advantage of cool temps and strong legs.
Heading up Iron Mountain, I was a bit worried about not using poles. After Hardrock, I was well accustomed to poles, but I decided I would see if my power hiking with hands on knees might be faster.
After descending off Iron, you have to make a decision exactly where to leave the trail and go up Cone Peak. Turn 50 yards too soon and you have to bushwack a bit, turn too late and you added distance. I picked a perfect spot and made it quickly above treeline. My legs and lungs were screaming as I made the steep climb to the top.
Leaving the Summit of Cone, I look a nice diagonal line of descent towards South Pk and Echo peak. Having just run the loop a couple weeks earlier, I navigated the tree sections without any bushwacking, submitting South and then Echo (north shoulder of Echo as the route does not require the short traverse to the true summit) before heading along the ridge above Echo Basin. I nailed this traverse without any missteps or route finding issues in the trees. When I made it to North Peak (south shoulder of North as route does not require the short climb and bushwacking to summit) i welcome the fun drop into the Basin where I refilled my water bottles from my BeFree filter and took off down the trail.
The trip down the Echo Basin gravel road and Santiam Wagon road was quick and uneventful. I was running well and feeling great. When I got to Hackleman Rd, I topped off my water at the small creek next to the road instead of the main river below to save a minute or more from my prior attempt.
I then started the long 3ish mile climb up to East Browder Ridge. I ran/walked the road section, stopping one more time to refill my BeFree before heading off the road and up the very steep climb to Browder Ridge. This climb hurt. My legs were screaming and my low back was aching on the final steep pitches, but eventually I made the ridge and started traversing over to the official trail.
I made a couple of minor navigation errors through the trees in the last section before you get to the final ridge that takes you up to the meadow below the trail that heads to Heart Lake. I can save a minute or two in this section as the route gets more use and is easier to follow.
Once I made it up to the trail, I knew I had one last climb to the saddle before the rest of the trail descends most of the time to the finish. I picked up the pace and moved well for the next couple miles of rolling terraina and when I got to the last two mile drop to the finish, I knew I had sub 6 hours in the bag. Since that was my goal, I struggled to push hard to the finish, but I kept it rolling all the way to the car, finishing in 5:46:34.
I would say a top level ultrarunner could go sub 5 hours. I will try to go sub 5:40 this fall.