JMT from Tuolomne to Mammoth in a Day

JMT from Tuolomne to Mammoth in a Day

Page Type Page Type: Trip Report
Date Date Climbed/Hiked: Aug 4, 2012
Activities Activities: Hiking
Seasons Season: Summer

The Idea

Call me a recovering climber. One thing that always killed me about mountaineering trips is the weight of all the gear. From the plastic boots to the rack of gear to the rope and, since I'm a photographer, the cameras and big fat lenses. I never enjoyed the approaches. Actually, that's an overstatement. Approaches are miserable for me. I've always been skinny - sport climbing was my forte back when I was fit and young - so 50 pound plus packs always just kill me.

I do love the high-country though and have taken to various one-day peak bagging ascents and long fitness days in the mountains. I've entertained the idea of hiking the John Muir Trail but a) I haven't had the three weeks available to do it and b) carrying a big fat pack for three weeks never appealed to me. Instead, after looking at a topo for some long day treks, I had the bright idea to do the Tuolomne to Mammoth portion in a day. Looked doable so what the heck I figured.


I decided that I didn't want some dawn to midnight slog so instead I decided to run as much of the trail as I could. I mapped out and dissected the 28 mile route from Tuolomne Lodge to Agnew Meadow. I'd take the JMT to Thousand Isle Lake and then take the PCT High Route to the stables at Agnew Meadow where I could get a ride to Mammoth.

My idea was to run the flats and downhills and then just power hike the passes. After about five weeks of training, I brought my running up from maybe 6 miles a week to 50 miles per week. Ideally, I would have given myself more time, but that's all that my schedule permitted. The challenge in upping my miles like that was that I ran the risk of injury. I'm not a kid anymore and my body can't take the punishment of training like it used to so I had to be careful. I kept away from training on hills - except for a couple of prep hikes/runs (one up 10,800 foot San Jacinto in So. Cal).

For gear, I chose a Camelback Hotwire Pack. Lightweight and easy to run in. I traded in my Sportiva trail runners for the Asics Fuji Gel Racers. That shaved 6 ounces off my feet. I think they say every ounce on your foot is like ten pounds on your back (or something like that). To avoid blisters, I used Injinji socks which are like gloves for the toes. They worked great under my regular running socks. For water, I used the Sawyer Filter. I was planning on using a UV pen, but the Sawyer was light enough and was easy to work with my Camelback system - which the pen wouldn't.

I carried an emergency bivy sack just in case along with a roll of tape and plenty of Gu packs and easy to digest snacks, a couple of bananas and electrolyte replacement powder for my water.

Tuolomne to Donohue Pass

I started at 6:00 am - at first light - on August 4. In the Lodge parking lot where people line up for JMT permits, I chatted with a guy waiting in line. He asked where I was going so I mentioned that I planned to be in Mammoth that afternoon. He responded, "You know it only takes an hour to drive there." The look on his face when I told him I planned to run it was priceless. By the way, no permit is necessary for day hiking on the JMT.

Running the first nine miles of the trail was blissful. Cool early morning. Mammoth Peak keeps the sun off the trail for some time. The trail is barely uphill so it makes for a pretty easy run. I came up only two days before so I wasn't sure how I'd do at altitude. I turned in 13 minute miles on this section which was only a minute south of my training pace. Not bad for the altitude and the extra weight.

Right at mile nine (according to my GPS watch - I love my Garmin 310 XT), the trail kicks up pretty drastically. No more running. There's a steep section then it backs off. My main concern was water since I'd brought just enough to through Donohue pass. I ended up filling up fairly low - at a bridge where the trail crosses the creek. Turns out I should have waited because there's plenty of water up until about a 1/2 mile from the summit.

The steepest part of the trail was the initial kick. After that the trail was pretty smooth and gradual to the summit. Although I didn't run it, I felt pretty good all the same - my pace was about 20 minutes per mile nearing the top. Reaching the top of the pass took exactly four hours. By the way, I got five bars and 3G with my ATT iPhone. Had to text a photo to my girlfriend who was heading to Mammoth to pick me up.

Donohue Pass to Agnew Meadows

The descent from the pass was steep and rocky. The main challenge was just not to stumble and faceplant as I ran and bounced along. Not easy after 14 miles on the run. Eventually, the rocky trail gave way to more forgiving meadows and a more gradual slope. At this point, my Achilles tendons - always a concern during my training - began to flare with pain. Nothing I could do about that I just ignored it and hoped it wouldn't get worse.

Eventually, I reached the next, much shorter and easier Island Pass. Here's where my lack of training began to show. Though I kept moving, I slowed down to about 32 minutes per mile. The warming day didn't help either. Although the pass is fairly short, it sort of drags on up and down as it approaches 1,000 Isle Lake. I suffered more on Island than I did on Donohue.

After seemingly forever, I made it to the Lake and the 20 mile mark. I was 6 hours into it at this point. Unlike my last visit about a month earlier, this time the mosquitos, that had literally chased me away in a mad run, were pleasantly gone. I filled up with water again and took my only sit-down rest for the day - about ten minutes. I chatted with a day hiker who encouraged me with a "You've got this!"

I was actually feeling pretty good to this point. I turned off the JMT and onto the PCT. A mile out from the lake, I made my one misjudgment of the day. Instead of heading down the valley route into Mammoth, I decided to strike out along the PCT High Route. According to my reading of the topo, it appeared to be a long downhill into Agnew Meadow. Wrong. Instead, it kept going up and up and up and even switchbacked up the mountainside. By mile 25 I expected to be enjoying a nice steady downhill run into the finish. Instead, I seemed to be marching ever uphill.

Realizing that I hadn't peed for several hours, I started drinking more. I ran out of water along the high trail - and was happy to have my water filter as I filled up at a small trickle that crossed the trail. While the high trail offers beautiful views, it's also heavily traveled by horses so it stinks and it's torn up by the horse traffic. No way would I have drank water from there without a filter. I should also mention that the trail there gets sun all day and can no doubt get pretty hot. In my case, a summer storm blew in so, instead of the hot sumer sun, I stayed cool with an occasional sprinkle and increasingly darker clouds.

The trail finally heads sharply downhill at the last mile or so. I was happy to run the last dusty switchbacks and be done with the high route. I stopped my watch at 9 hours, 13 minutes for the 28.5 miles. Total moving time was 7:45. Average pace was 19 minutes per mile including stops. Average moving pace was 15 minutes per mile. I feel like I could have shaved an hour off my time if I'd taken the low route. Oh well... next time.


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