6:05 moving time. 50s and drizzly the first couple hours then just overcast. Started a little before 8am at MMSF trailhead. Wore shorts, and t-shirt. Started with arm warmers, hat, and gloves but took those off about a mile in and never needed them again. Lucked out on the weather for December. Realistic challenging goal was 6:15, but my ultimate goal has always been to be under 6hrs. I wanted to be more aggressive this year and know at the end I had given it my best effort. Started off feeling very good. Legs were fresh. Was sweating a lot quickly and HR was a little higher than I wanted. Just went by effort. Hit bear lake at 87min and refilled water. I was looking for the trail and couldn't find it. I saw blazes along bear lake but knew that wasn't the trail. Tried to find the trail again and couldn't so just took the path along bear lake. It was clearly blazed in 3 spots so I'm sure that's a new reroute. Just wish I had known. Continued to feel good and move well. Started getting a little tired on the uphills around 2hrs, but nothing unusual. Got to 45 at 2:37:30 and refilled water after 45. At 20.5mi I was at 2:57. I thought there was a tiny chance I could get 6hrs if I went for it and had an unbelievable day and could hold on. Let myself push to see what I could do. There were multiple instances where the leaves were deep and the trail not very visible that I had difficulty figuring out where to go. Got to yellowwood lake rd at 4:05 and the south end of yellowwood lake at 4:24. All was going well and I was feeling good until the south side of yellowwood lake. I stopped to refill my water, and I was dizzy and lightheaded. I pushed it out of my mind and kept going. I was definitely spent going up the next hill and knew it was going to be a sufferfest to the end. I could still get going on the flats and downhills but the uphills were rough. Everything slowly went downhill. Hit 46 at 5:04. I couldn't move very well on the next trail section and was struggling. I really wasn't sure if I was going to make it to the end or faceplant or pass out. Missed one turn that cost me about a minute even though I knew to pay close attention through there. Got to crooked creek TH at 5:52. Struggled up the hill and struggled all the way to the finish completely spent. Walked back initially very slowly and unsteadily but then was able to shuffle some of the flat sections. I'm very content with this run and effort. I might have been able to run a little faster if I would've settled down a little in the middle. But then I wouldn't have been sure I couldn't have gone any faster. This way, I know I couldn't have gone faster and that makes me satisfied. I wanted to leave it all out there. I don't feel any need to come back to to try for a faster time on this trail in the future now. 6hrs will have to be for someone else.