Hike Iron Mountain via Heaton Flats


Hike Reports, LA / SoCal Trails / Saturday, December 19th, 2020
HIKE TO: Iron Mountain (aka Big Iron Mountain, Iron Mountain #1)
TRAIL: Heaton Flats Trail > Iron Mountain Trail
MILES: 13.94 miles (out & back)
TIME:  4:37 hours up, 3:!6 hours down
DATE I WENT: 12/13/20
DIFFICULTY: strenuous
ELEVATION: 7981 ft
ELEVATION GAIN: 5981 ft (6856 ft gross)
PARKING PERMIT: yes
LOCATION: Angeles National Forest/ Sheep Mountain Wilderness

A little background about my current mindset going into this hike – click here to skip straight to the Iron Mountain via Heaton Flats Trail Report below.

Last weekend, I summited Southern California’s hardest hike, Iron Mountain via Heaton Flats in the San Gabriel Mountains. This is a hike that I’ve avoided for years because I knew it would be a sufferfest… so why now? After two unsuccessful summit hikes recently, I felt like I needed a win… not just any win, but a physical challenge… you know what I mean?

The previous weekend, I attempted C2C and was 3 miles shy of the summit when we had to turn around due to a late start and lack of time. The weekend before that, I attempted Mt. Whitney and turned around at the beginning of the switchbacks because it was too cold and one of my feet was numb. C2C is a harder/longer trail but Iron Mountain takes the cake on being SoCal’s hardest hike as there are many easier trail options to get up to San Jacinto Peak… as opposed to Iron Mtn.

I’ve attempted Iron Mountain via Heaton Flats twice in the recent past:

  • In June 2019, we started the hike but turned around early on because we started late (a bad habit of mine in the last year or two), it was hot, and most of all the flies were horrendous (I think it was horseflies but I got large bites all over my body, worse than mosquitos).
  • In Feb 2020, I tried my second time but again had a late start and with the shorter days, I wasn’t prepared to hike down in the dark. I actually made it almost 5-miles-in and should have just gone for it, but if I’m being completely honest… I just didn’t feel like going any farther

When I first started hiking back in 2015, my mindset as a hiker was completely different than the hiker I’ve evolved to now – I was a summit-or-die-girl. I never gave up on any peaks and hated the idea of turning around – I would rather suffer through it than turn around. I was also only hiking once a month at the time and every hike was something new for me so maybe it was just more exciting to hit all the peaks then. Nowadays, I make time to hike every week and have explored so much that my purpose is more just to get outside away from civilization, surround myself with the calms and beauty of nature, and get some exercise while I’m at it. I’m ok with turning around on hikes now but I need to stop making a habit of it… the mountains will always be there, and not every hike should be a sufferfest to the summit for me anymore. I’ve become more of a leisure hiker/explorer, just getting out to the mountains is enough.

Looking back, I should have hiked Iron Mountain that first year when I was training for Mt. Whitney.

I was determined to make it to the summit of Iron Mountain this time (sometimes called “Big Iron Mountain”) – my body felt like it was at its peak for the first time this year. With Covid-19 closures and all the wildfire closures, my stamina has been low – I’m still getting out often, but the exercise level just isn’t the same – the lack of gym access doesn’t help either as I used to workout every day to maintain my endurance for the trails.

Iron Mountain Trail Report

Please note that every tracker varies in it’s recording details and although most blogs will say the trail is roughly 7-7.5 miles one-way with 6600-7200 ft elevation gain, this write-up is based on my tracker which comes in at 6.9 miles one-way and 6856 ft gross elevation gain

The trailhead for Iron Mountain via Heaton Flats is the same as the Bridge to Nowhere Trail in the San Gabriel Mountains (East Fork Day Use Parking Area) and you need an adventure pass for parking (or your National Parks Pass works too).

We started at 6:16 am in the dark and caught the sunrise on the trail. The trail starts on the wide, flat, East Fork Road for about half a mile before you take the Heaton Flats Trail on your right. The Heaton Flats trail starts with an incline so we were able to un-layer all the way very quickly – it’s been a warm and dry December in LA. The first 1.2 miles on this trail climbs 989 ft before reaching the first open section which we arrived at 7:02 am (1.7 miles from the trailhead). Now, you enter Sheep Mountain Wilderness.

The trail continues up and down (but mostly up) along the ridge for 2.41 miles with 1694 ft elevation gain until you start the 0.25-mile descent to Alison Saddle, with an elevation loss of 149 ft. Alison Saddle is about 4.38 miles from the trailhead and sits at 4571 ft. Some people choose to stash water here for the return hike, but it’s a good spot for a break regardless as the climb ahead of you is strenuous.

This is where the Iron Mountain Trail gets really grueling. There is still 3410 ft of elevation gain to climb in the next 2.59 miles! The trail is very steep, relentless with loose gravel and rocks, and has little shade… it’s the ultimate booty-blasting trail that keeps on giving. Once you get to the false summit, you’re less than 10 mins away!

From the peak of Iron Mountain, you get 360° views with Mt. Baldy to the West, Rattlesnake Peak to the East, and the San Gabriel Mountains all in-between.

It took me 4 hours 37 mins to hike to the top. Getting to the saddle was surprisingly easy on my body because I made sure to be constantly snacking on my oat bars at least every hour (even forcing myself to eat when I’m not hungry) and the strenuous hike from the week before also helped train my body, but the last 1-1.5 miles is when I really started to feel the burn – I guess it’s true what they say, the last two miles are the toughest. The last mile alone has an elevation gain of 1316 ft (the last two miles has a total elevation gain of 2612 ft)!

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The peak was very crowded but we were able to find a small spot to the side to ourselves. After enjoying the summit views, embrace yourself for the long and steep hike down…

Trail Condition & Going Down

If I’m being honest, the terrain was better than I expected. Everyone says that you fall a lot of this trail so I was expecting it to be a lot worst, but I’d say only from the saddle and 2 miles after are the slipperiest parts – don’t get me wrong, it’s all super steep going downhill and killed my knees, but those two miles were really bad (I hiked down super slowly).

Tips for hiking down to save your knees:

I’ve gotten several messages about this on social media and probably don’t have any new ideas for you.

  • Trekking poles are always good going downhill to take some pressure off your knees but I personally have a hard time hiking with poles – it makes me feel handicapped and I end up relying on the poles too much and move much slower BUT it does help the knees.
  • I also heard microspikes work well for the slippery parts… personally, I’m not trying to ruin/dull my microspikes on all the loose gravel/rocks but I can see why others use it.
  • For me, the most helpful thing was to never lock my knees going down – I have a habit of stomping and applying a lot of pressure on my knees when I’m hiking downhill so this definitely helped – I did fall once but I expected to fall 3x+ so that’s a win still. With my knees constantly slightly bent when hiking (not-locking), it does feel more strenuous on my thighs though… it’s like the mini-squat that never ends.

If you have any tips on downhill hiking, I’d love to hear your thoughts in the comments below!

Some Other Thoughts

There was a ton of trash on the trail – we saw tissues and masks hanging along the side of the trail and some hikers we met even told me they picked up 5-8 lb of trash (thank you for doing that)! Please remember to pack out what you pack in – the outdoors is not our trashcan and if you can’t respect our playground… don’t go play. Many of us seek time outdoors to get back in touch with nature but it’s harder to enjoy when it looks like a dumpster.

There was a group of 20-30 hikers/ trail runners. I was shocked at how many people are on this trail especially during these times. I was hoping to get some peace and solitude out in the mountains away from people and thought I picked a good trail for it. Although there were few people along the first half of the trail, the latter half and summit were well-trafficked.

Lastly, my legs were sore for 2 straight days after – I mean… it really ached to move at all and when I had to, I walked around like Frankenstein >.< But it was only day 4-5 that I started to feel normal again. Even though I felt great during the hike….post-hike kind of sucked 😛


Gear I used on this trip:

Thanks for reading!

I’d love to hear your comments, suggestions, and any comments below! Please don’t forget to practice leave no trace! 🙂

10 Replies to “Hike Iron Mountain via Heaton Flats”

  1. Great write-up once again, this time on your Iron Mountain adventure. Kudos on summitting such a strenuous trek! Word to the wise: our local San Gabriel Mountains have always been plagued by those annoying deer flies from mid June through mid Sept—our hiking group avoids that area along Angeles Crest Highway through the Wrightwood area. The area least plagued is the Mt Baldy region; thus from mid June till about mid Sept our group is usually only on the trails in the Baldy region (plenty of treks available there………)

  2. Also happy to hear about the change in mindset……remember the time tested axiom: ‘It’s the journey and not the destination’. I have also enjoyed more along the hikes than at the actual summit of any mountain. By the way, the most incredible two spots I have ever seen are:
    1). The view into Kings Canyon from the top of the Kearsarge Pass (5 miles one way). This sight is beyond a postcard.
    2). The view from a Mt Waterman area (just below the summit) where there is a large pile of huge boulders; atop these is an unsurpassed 360 degree view. Found this spot years ago while tailing a group of BigHorn sheep through this natural maze of rock……
    And…..the reason there are fewer flies in the Baldy region is due to the ladybug migration which goes through that region every Spring……along the IceHouse Canyon trail in April and parts of May some of the boulders are completely orange due to them being covered by millions of these interesting ‘fly-devouring’ creatures….

    1. I’ve seen my fair share of ladybugs in the region for sure & I wholeheartedly agree that the journey is just as important, if not more, than the destination at times! Kearsarge Pass certainly offers incredible views, it’s where I did my first solo wilderness overnight hike! TBH I wasn’t a big fan of Mt. Waterman area but maybe I’ll have to give it another chance. Thanks for sharing!

  3. Very cool,nice read and congrats for making it. Your right about sometimes its better to turn around if you don’t feel right about hike. There is always another day.

  4. HI TIFF: AFTER A STRENUOUS HIKE I HAVE THE SLOWS FOR A COUPLE OF DAYS. BUT IT IS BETTER THAN HAVING THE RUNS. I MIGHT HIKE IRON IN EARLY APRIL. A TOUGH HIKE IS BEHIND THE LIBRARY AT BRAND PARK IN GLENDALE. UP DIRT TRAIL TO DIRT FIRE ROAD. THEN DOWN DIRT FIRE ROAD CALLED BRAND PARK MOTORWAY. 8.2 MILES ROUND TRIP.
    I HAVE HIKED BALDY 32 TIMES. BADEN-POWELL 43 TIMES. THERE IS A GREAT BIG BEAUTIFUL TOMORROW WAITING AT THE END OF EVERY DAY. WHEN I GROW UP I HOPE TO
    TO BE BIG AND STRONG. IN 8 MORE MONTHS I WILL BE IN THE 94 YEAR OF MY YOUNG LIFE.
    I HUFF PUFF AND GRUNT. I CAN’T KEEP UP WITH FAST GUYS HIKING UP IN FRONT.

  5. Hiya, I have hiked Iron Mtn 3.5 times at my peak health; similar to when you were active multiple times per week. The half was unsuccessful and I turned around from exhaustion. Trail tips: always bring a flashlight for sometimes it may get too dark on the return trip, hike in a zigzag pattern on the way down to take some pressure off your knees & go on your butt and step down slowly for the steep/slippery sections. Last part works well in snow hikes too with either a pole, ice axe or shovel. It’s good your return hike to Iron was at 6-ish am, that’s a good start time for strenuous hikes. Thanks for sharing your journey. 😃

    1. Hi Long, thanks for all the tips, I practice most of those already! Even without summiting, Iron Mountain is a beautiful hike nonetheless 🙂

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