Heaton Flat Trail to Iron Mountain

HARD 57 reviews
#32 of 191 trails in

Heaton Flat Trail to Iron Mountain is a 12.6 mile moderately trafficked out and back trail located near Azusa, California that features beautiful wild flowers and is rated as difficult. The trail is primarily used for hiking, walking, nature trips, and birding and is accessible year-round. Dogs are also able to use this trail.

12.6 miles
6338 feet
Out & Back

dog friendly



nature trips




wild flowers


Directions from Azusa, CA: Travel north on Highway 39 for about 12 miles, turn east (right) onto East Fork Road and travel 6 miles. Entry is from the East Fork Trailhead adjacent to East Fork Fire Station.

22 days ago

Hiked up April 1, 2018 (Easter Sunday) with my little cattle dog, Vedder. Had hiked Rattlesnake a week prior and slammed Iron into my head all week long as a mental preparation.
This hike is no joke. For being 26, in “average” shape, this trail really put it into perspective for me. Towards the top I would take ten steps and break for 15 seconds. Once you turn that rock at the top to see the lonely summit pole, it all hits you though. Tears of joy.
Started at 5 am by headlamp and was back to the car at 4 pm. Be sure to dunk you’re entire head and face in the east fork San Gabriel river after exiting the Heaton Flat Trail on the way back. My god that felt so good. Good luck!

2 months ago

Before doing this hike, get mentally prepared for the challenge! This hike shares the parking lot with "The Bridge to Nowhere" folks. Hike/walk past the yellow gate for 10-15 minutes until you see the bathrooms on the right. The trailhead reads "Heaton Flats Trail" and is located just past the bathrooms. Like many other reviewers mention - Bring AT LEAST 2 gallons/ 7-8 liters of water, wear long pants, and hiking poles. After the first 3 miles or so, there are MANY hills with several ups and downs and the Yuccas are unforgiving throughout the entire hike! I drank more water on the descent than on the ascent. I've never had knee problems but both of my knees took a beating (And I used hiking poles)!

For me, this is a love/hate hike. I loved it while on the ascent but hated the descent. It was definitely worth it once on the summit with the 360 degree views.

2 months ago

I wasn’t able to complete this hike because I didn’t have enough food and daylight to complete it, but this hike is a straight up relentless beast. It seems easy at first, but it gets mentally challenging as you go. This hike will get you questioning if you should turn back or not. The last mile is 2,000 feet of elevation gain. I can’t stress enough how crucial hiking sticks are for this trail. You will need them for the steep incline, and on the way down. Also, the trail can get narrow at times with lots of yucca plants. Wear long pants! The trail blazers of this trail really tried to mess with us hikers. Instead of going around the hills, the trail goes straight up over the hills only to go right back down which kills your determination even more. I will be doing this hike again to complete it, only next time I may bring overnight gear.

3 months ago

TLDR: Very intense hike. And not just due to the elevation gain. The chaparral will try to scratch, scrape or otherwise impale you from every angle. Excellent training for other steep hikes.

Nice paved parking area with chemical restrooms. Huge flat dirt path from the parking area to the trail head. You could walk path to get the blood flowing while cameling up on some water then stretch out at the trailhead.

The trail from the trailhead to Allison Saddle is very reasonable. It is wide and not technical. It is moderately steep, but not worse than any of the prerequisite hikes for this one like Mt Baldy via Ski Hut and/or Old Baldy Trail, San Gorgonio via Vivian Creek, Three T's or San Jacinto. After about the 2 mile mark, the view opens up providing some great motivation to press to the summit.

All the above changes once you reach Allison Saddle. The trail narrows and you'll get very acquainted with the chaparral. It's not overgrown and no bushwhacking is required, but you may get stabbed more than once. Also the trail steepens significantly while footing gets quite loose in spots. Think along the lines of the first mile of Vivian Creek or that one section of Ski Hut Trail we all love so much. It's like that all the way to the summit. 35 degree plus incline in some sections.

I found the summit to be quite rewarding. You will be able to see most of the notable peaks in the area. If you're lucky like I was, you'll see snow on West Baldy. It's quite picturesque. Not only is the view excellent, but the feeling of tackling Big Iron is pretty great in and of itself. I actually relaxed up there for an hour eating, taking pictures and relaxing for what I knew was to come.

The descent back down was worse than the climb. It's downright slippery all the way back to the saddle. If I had left my trekking poles at home I would have been cussing at myself the whole time. This was the only hike I have done recently that I actually took a break coming DOWN the mountain. Once at the saddle, its a roller coaster hike back to the car. After the previous section, I found it quite relaxing.

All in all this was an excellent hike. But I went there for training for C2C and Whitney. Had I went there for just a fun day hike like say San Gorgonio, I would have been slightly disappointed. This wasn't fun. BUT it was rewarding and I am proud to say I tackled Big Iron once and for all. Now on to bigger and better things. I may revisit Big Iron a week out from C2C, but probably not before that. I'll stick to Old Baldy Trail and just hike it faster and/or with more weight.

3 months ago

Walked from the parking lot down the dirt road to the Heaton Flats Trail head and took the trail all the way to Iron Mountain. To give a good perspective on it's difficulty, I'm a 20 year old 6'1" 180lb male who plays rugby and works out 2-3 times a week. I hike/backpack probably 5-6 times a year and I barely was able to complete this trail and my legs were cramping severely a mile before the summit. My brother is a 22 year old 6'2" 205 lb male who is similarly physically active but has had a couple more years of drinking, so he's not in as good of shape. He gave it all he had but stopped about 1 mile past Allison's saddle after getting nauseous and his muscles cramping. That being said, the views were awesome and I would do it again if I can get into better shape first. So, if you enjoy pain or are in a lot better shape than me, give Iron a run for her money. Also, the hike took us a full 9 hours (probably would've been a little faster without my brother but who knows).

4 months ago

the c2c is way easier then iron mountain and I do up to 22 mile hikes but this hike was very difficult and I ran out of water I had a little less than a mile to go I was at 12.35 but do to the time and the early nights we had to turn around cause it just as difficult going down as up, this is the first time I've ever ran out of water. Do the C2C to prepare for this hike. You can be the best hiker but there is a trail out there that will kick your butt!!

4 months ago

This is a five star trail mainly because I like climbing steep hills and this mountain met that expectation. If you don't like hiking up steep hills then this hike is NOT for you. The view was as good as any other mountains in this area. A friend and I did this fun hike today. We completed it in 5 hours 30 minutes. It exceeded my expectations. A solid and fit hiker should expect to complete this trail in 7-10 hours.

5 months ago

In preparation for C2C, my group and I conquered Iron Mountain. This was my second time on the Heaton Flat Trail. I hiked solo up to the Alison Mine Saddle last year in preparation to do the entire hike with two other hikers. Unfortunately, it never happened.

So, on Saturday, Nov 4th six hikers and I set out to conquer this beast. I can honestly say the Iron Mountain certainly lived up to its billing as being the toughest hike in the San Gabriel Mountains. The final two plus miles to the peak were steep and relentless. I had no doubt we would make it, but I seems like the last two miles just went on forever!

For our efforts, we were rewarded with some of the most awesome views of all the surrounding ranges and peaks. We had perfect weather and very little wind at the peak. It was probably in the 40's at the top and never got higher than 60 throughout the hike.

We each carried between 4 to 6 liters of water plus a liter or so of electrolytes or coconut water. We have C2C in two weeks. It will be my second summit from the Skyline trail and my groups first time. It will also be my 8th summit of San Jacinto (from various trailheads).

Iron Mountain - I've got your number now! See you again next year as my Hike Beyond the Hills friends and I conquer you again. ;)

5 months ago

Good hiking, panoramic views, slows you down on your descent due to loose rocks

6 months ago

Just completed Cactus to Clouds on 10-14, my first time. Had never done Iron Mountain so I figured, why not while I was on a roll. Started at 7:15 am, and it was a chilly 50 degrees. Didn't take long to get warmed up. The first 4 miles are moderately difficult with lots of beautiful, distracting scenery. I snapped over 100 pictures during this hike.

I brought 3.5 liters of water and no other food or drink. When I reached the saddle point before the 2.5 mile ascent, I stored 1.5 liters of water in the shade to minimize the weight I would have to carry up the steep grade. I made the mistake of carrying too much water on the Skyline Trail portion of C2C the prior week, and the weight made the ascent up the last 2 miles to Grubbs Notch pure hell.

The last 2.5 miles of Iron Mountain exceed the difficulty of the last 2.5 miles of C2C in terms of steepness. However, C2C you have to travel 8 miles up steeper terrain before you reach that last 2.5 mile segment up to Grubbs Notch so you begin that ascent far more tired than this one.

Nevertheless, this was a beast. Many times when I had to use all fours to climb up the loose dirt and gravel up grades of 70 degrees. Fortunately, as you ascend higher, the temperature drops. It took 4 hours 45 minutes to reach the summit, and it was about 60 degrees at the top. The pace was leisurely enough that I did not feel as drained as I did at Grubbs Notch the week before.

Mt. Baldy seems close enough that you want to just keep hiking to notch another summit for the day and avoid having to descend those dreaded steep trail sections you just came up. The views are spectacular from the summit, and I rested for 20 minutes soaking up the scenery before heading down.

You have to be very, very careful on the descent. Practice landing on the balls of your feet instead of your heel, and you will avoid those nasty wipeouts where you slide forward and land hard on your butt.

Many portions of this trail are very narrow because brush branches are growing over the trail. Lots of prickly yucca plants and other scratchy plants were a nuisance since I was wearing shorts and short-sleeves. Long sleeves and long pants would minimize this problem.

By the time I reached my stored water, I had gone through my 2 liters so I poured the remaining 1.5 liters into my camelback and headed back. Total time was 9 1/2 hours. Wished I had done this before C2C. It would have been better preparation than the Bear Canyon Trail up to Baldy.

I will be doing it again soon.

6 months ago

Finally got out to do this one. A beast it sure is. They don't call it big bad iron for nothing. Be ready for this one. I also got 14.6 miles round trip from the parking lot.

7 months ago

A pleasant stroll alongside friendly Yucca plants that greet you throughout the trail.

If you're seeking yourself and the answer to life, the universe, and everything, Big Iron is calling for you. The scenery is beautiful and full of surprises. This hike is like a roller-coaster that leaves you wanting more.

This was my first solo hike. I wouldn't recommend ever doing this solo unless you're crazy like me. The solitude was priceless yet unfamiliar. I didn't see a single person all day long, but I did see a lot of poop and birds like quail running across the trail. I started and ended in darkness 6AM-8PM. My flashlight died as I lost sight of my car so check your batteries unless creeping through the shadows is your thing... The forecast called for a sunny day, but I was embraced by an epic thunderstorm 2.5 miles in. I bowed in awe as lightning waltzed around me. The temperature dropped precipitously then I showered for 30 minutes. It turned out to be a beautiful morning with rainbows and sunbeams streaming through the clouds. The real fun began as I started ascending Big Iron itself. The wind pushed me around and tested my balance during the final mile. It was a neat day in nature.

As a side note, the actual mileage and ascent is around 13.6-14.1 mi and 7355 ft according to GPS devices and other sites.

8 months ago

Brutal. Love it! Good prep for C2C or Whitney. If you can conquer this in 6 hours or less then you can easily do Whitney. Last three miles of the climb are pure amazing pain. Bring 6-7 liters of water and store the water just before the climb. Take 3 liters for the final climb. Don't underestimate the climb. Remember, you have to go down what you climb.

Monday, April 24, 2017

Per Garmin GPSMAP64:
Distance: 13.6 mi from the locked gate and back.
Total Ascent: 7355 ft. (a few ups and downs)
Minimum Elevation: 1939 ft
Max Elevation: 8009 ft.

Nice weather made the hike very enjoyable.
If you are using hydration pack, make sure to either bring extra water bottles or be aware how much water is being consumed. Ran into a hiker who had to turn back because he ran out of water. My wife and I brought 6 liters water and two apple juice for both of us and we had 1/4 liter remaining at the end.

Watch out for ground level branches. We bruised our shins from them while concentrating avoiding thorny yucca plants. Be careful during descent. It is very slippery at places.

Monday, April 24, 2017

You may bring plenty of water. The trail is quite hot. I bring 7.8L and left 1L. But it is due to I camping on the Allison saddle at night, when the trail is cooler. After Allison saddle, the trail is steep but relatively safe. The top is approachable if prepared well. Amazing view at top. You may also bring a glove to avoid possible bleedings from yucca.

Tuesday, April 18, 2017

Strenuous, but amazing views.

Here is a quick video of Heaton Flats Trail


Sunday, March 26, 2017

ayer logre conquistar Iron Mountain por primera vez y lo logre en 5 horas ida y vuelta y si q esta pesada esta muy dura pero si se puede

Saturday, February 18, 2017


Monday, November 28, 2016

Thanks to the cruel reviews and there were just a few reviews on this trail .. I had to go see myself and all I can say is brutal steep on 45degree angles at one point and those yucca plants penetrates you like needles.. but we made it 11 of us started together at 5:30am all the way to the summit made it all together to the star point at 3pm it was 15 miles 10 hrs weather help a lot a little rain hail and some snow flakes.. wind was just perfect to keep us cool of our own body heat . I am amaze of how difficult is this trail... IRON MOUNTAIN HAS BEEN CONQUERED thank you LORD.. 11/26/16

Wednesday, November 23, 2016

Not HARD like Mt Baldy ...
After I passed the fork for the bridge to nowhere, I did not pass a single person

First 3 mi are wonderful just for the views

I HATED this trail solely for the fact that I was constantly attacked by the plants from my face to my toes after that (my poor dog ... who hikes with me and can last up to 16mi was miserable). The terrain turns to sandy and sometimes steep covered areas ... so you lose the wonderful view.

I wanted to get to the top, but I was bleeding from the plants and was annoyed ... turned back early.

Much better, challenging,rewarding trails out there. Though if I lived close by .. I would consider doing a 6 mi out and back trail run.

Thursday, November 10, 2016

This hike. Till now is the most difficult hike i have ever done
We did 6 hours. Just to
Get to the top me and my friends.
We star 5am and we get back at 4:45pm

Almost 10 hours hike.
If anyone is planning to do this hike
Please. Carry a lot of water. You might need easily 7 litters.
Don't take big iron mountain easy.

Thursday, November 03, 2016

This hike should be on the six pack of peaks (SoCalHiker.net). In the past few weeks I've climbed Wilson, Cucamonga, and Baldy, and this was MUCH harder than those. The first 4 miles are OK, but then the trails climbs to about 45 degrees, with slippery rocks, lots of yucca plants , that have grown into the trail, and at many points the trail is very narrow due to shrubs and trees growing on each side, making trekking poles useless at those points. I slipped a good 6 or 7 times on the way back down, and was just lucky to not slide into anything prickly.

I planned on doing a loop down the other side and to the waterfall, but couldn't even make it to the summit. Temperatures went from the low 60's on the way up to low 80's on the way back down, and it was windy and chilly towards the top. Got to 7800' and was too wet and cold to finish. Started at 7AM, called it quits a little before noon, back to the car at 3. Bring more water than you normally would. I burned through 3 liters and ran out with 4 miles left to go.
I give this 3 stars because of the yucca plants :) and because even the descent was a challenge, and a bit dangerous at times.
I'll be back to finish this one after I get some proper cold weather hiking.gear.

Tuesday, November 01, 2016

This was my third attemp to summit Big Iron, and for me, the difficulty of this hike was second only to Mt. Whitney. Started in darkness and ended the same way. Took a hard fall on the way down one of the crazy steep sections above Allison Saddle. I doubt anyone comes down from this mountain without leaving a little bit of blood behind thanks to the spiney Yuccas hugging the trail. Great trail for solitude and veiws. Bring more water than you think you'll need, because you'll use more water than you think!

Saturday, September 17, 2016

Great trail recon today up the Heaton Flat Trail to just beyond the Allison Mine Trail (except the last two miles). I started out from the parking lot at 0645. It was about 55'. At 2.5 miles in it climbed to 69'. I covered the 4.98 miles up in just under 3 hours. The first 3 miles were pretty easy. From mile 3 to 4 is where you just go up and down, and up and down. Take some elevation from the mountain and then give some back. Not too bad though. Mile 4 to 5 is where the challenge began. The 60 and 70 degree grades showed up. There was a little bit of scrambling up rock and dirt too. I stopped just before the saddle. My goal today was to hike to the Allison Mine Trail. It was 85' by this point. Spent about 45 minutes resting, eating and taking pictures. Then I headed down! The first mile down is a slow process. At mile 7.86 the temp was 100'. By the time I got to mile 3 going down, I felt great and was moving at a pretty good pace. Not smart! Just under 2 miles and past the wilderness sign, I slipped and rolled my ankle. Needless to say I slowed way down. I waited to ice and wrap it until I got back to the car because I didn't want linger and let it get stiff. Yes I carry a wrap and ice with me on all hikes. Second time in a month I've had to use them too. Once for me (today) and once for a young lady who twisted her ankle coming down San Jacinto. Anyway, my total time for the hike (including breaks, lunch and pictures was 6 hrs 50 min. Total hiking time was 5 hrs 42 min. It was 95' when I finished at 1335. I'm guessing the final 2 miles to the peak would have taken about an hour each and have about a 2500 foot elevation gain. I carried 6.5 liters of water and drank 3.5 liters. Two of those were 16oz bottles with electrolytes. Glad I hiked it, but hoping I'll be ready and healed for Oct 8 when I go to the top of Iron Mountain with a fellow hiker.

Thursday, July 14, 2016

This trail is a BEAST!! There's a reason you don't see a lot of reviews. Not too many people attempt, nor finish. I hiked up in April started early and took me all day to complete. Finished about 7L of fluids and wanted more. .. The total elevation gain is a bit north of 7K... don't let the false summits fool you.. Also bring a pen to sign the log at the summit..

Thursday, March 31, 2016

This is considered the most difficult hiking trail of all the San Gabriel mountains according to some hiking books.

Monday, March 21, 2016

When they say this hike is difficult, they are understating it. This is a very tough hike.
We started at 6AM and got to the saddle by 8:30. Rested up, cached water and electrolytes and psyched ourselves up for the rest of the hike. The saddle is about halfway, but almost all of the gain is ahead of you.
We took off at 9 and summited at 1:30. Steep does not do it justice. It is up and up and up, except for the heartbreaking downhill parts. It hurts to give up every hard earned foot.
I tried this 3 weeks before solo and turned back because I was already an hour past my drop dead turn around time. When I summited yesterday I could have kicked myself when I saw how close I had been, if I had had the energy to kick myself.
The descent was not quite as slow as the ascent, but just as painful. It is steep and loose and rocky. Poles are a great help.
Plan on this hike taking at least half a day, 12 hrs. The distance isn't that great, but it is tougher than it appears on paper. But I'm a fat old man, your mileage may vary.
Take plenty of water. I carried 12 liters and stashed 5 at the saddle, my hiking companion took 4 liters and used 2 liters of mine. We came down from the summit almost empty and left 3 liters for the next people that get caught short. It is a hot, thirsty, dry hike, stay hydrated. It's a lot of weight, but you can drop some at the saddle and leave it if you don't need it on the way back for the poor soul who gets caught short.
If you think you're up to it go for it, but it ain't easy. I'm battered,bloodied and bruised, but mighty pleased. I'll be back when the memory of how tough it is fades

Thursday, May 28, 2015

This hike is difficult! Much harder than I was expecting. It starts out pretty calm but after a few miles it just starts getting steeper and steeper until you are standing there panting like a dog trying to figure out how in the world you are going to get up the next nearly vertical section of loose dirt and gravel. Be prepared for heat of you go in the spring or summer and take plenty of water. We ended up leaving a stash of water for our return trip so we didn't have to carry it up the steepest sections of the mountain. This was a good move. Get an early start. We took our time and took some long breaks along the way, but we were out there an hour before sunrise and didn't have much daylight left by the time we got back to the car. The whole time we were on the trail we never saw another person. If you're looking for a way to get away from civilization this is it. Take plenty of bug spray! The Mosquitos are as big as the crows and they are thick on every part of the trail.

Monday, February 02, 2015

Very few people on the trail. We hit the snowline.

Sunday, September 28, 2014

Very difficult hike, over 6,000 feet of elevation change. Best if hiked on a cool day as much of the hike is spent following a ridgeline. There is no water on this trail. Some hikers left water bottles along the side of the trail for use on the return.

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