Heaton Flat Trail to Iron Mountain

HARD 42 reviews
#33 of 146 trails in

Heaton Flat Trail to Iron Mountain is a 13 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.

13.0 miles
6781 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.

12 days 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. ;)

19 days ago

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

27 days 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.

1 month 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.

2 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.

3 months ago

3 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.

3 months ago

5 months ago

5 months ago

6 months ago

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.

6 months ago

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.

7 months ago

Strenuous, but amazing views.

Here is a quick video of Heaton Flats Trail


7 months ago

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

8 months ago


11 months ago

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

11 months ago

11 months ago

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.

11 months ago

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.