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Mount Heinen is a 10.3 mile lightly trafficked out and back trail located near Boise, Idaho that features beautiful wild flowers and is rated as difficult. The trail is primarily used for hiking and is best used from May until September.

Length 10.3 mi Elevation gain 3,795 ft Route type Out & Back

Hiking

Views

Wild flowers

Wildlife

Over grown

Rocky

Scramble

No shade

Description
Waypoints (0)

Mount Heinen is close to Boise in the Boise Mountains. It is one of the 4 peaks that make up the 'Grand Slam' (the others are Cervidae, Shaw, and Kepros).

Weather
UV Index
Daylight
Reviews (62)
Photos (124)
Recordings (50)
Completed (87)
Maja Basevic
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarGray StarGray StarTue Jul 07 2020
HikingNo shadeOver grownRockyScramble

It was pretty awesome out there today! The only thing I would say is wear something that covers your entire leg because there are spots where it is so overgrown and also there’s some barbed wire towards mile 5 that I noticed (and also tripped on coming back.. haha)

View Maja's Recording
Heather Morris
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarFri Jun 26 2020
HikingBugsNo shadeOver grownScramble

Great trail. Some areas were rockier then others and more over grown then others. Watch for bees and fire ants! I got stung twice and then accidentally put my stuff in a fire ants nest and got bit. Some loose baseball sized rocks towards mile 4 that cause me to twist my ankle so be careful! Otherwise the Indian paint brush is still out as well as tons of other beautiful flowers. Saw turkey vultures flying over head and had great views! I started at around 8am at 75 degrees and was coming down around 5 hours later in 90 degrees. Bring lots of water ( I brought three bottles worth and could have easily drank more) and sunscreen! I did not encounter anyone or anything else besides two lizards the whole time!

Isaac Bonney
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarGray StarGray StarSun Jun 21 2020
Hiking

First 1.5 - 2 miles were very tough. 3.5 hours to the summit and 5:45 total. Beautiful views.

View Isaac's Recording
Ariel Klainerman
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarGray StarGray StarThu Jun 18 2020
Hiking

Beautiful trail. The first mile is no joke, ~1200ft of gain and over some cruddy terrain. Each successive mile gets easier. Great views along the entire trail. Only passed one group the entire hike. Took roughly 2:20 to reach summit. 1:40 or so down.

Sarah Knapik
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarGray StarGray StarMon Jun 08 2020
Hiking

First 2 miles are brutal like other reviewers have said. The trail was beautiful once we got up to the trees - so many wildflowers Took is 5 hours to do the whole thing and the way down sucks on those steep sections for the last 2 miles.

ward tyczka
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarGray StarGray StarSat May 30 2020
HikingNo shade

First 2 miles are tough. After that it’s not as tough but it’s still a climb. Started at 7 am to avoid today’s heat. Bring plenty of water, it’ll take longer than expected.

View ward's Recording
Brandon Winebrenner
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarMon May 25 2020
HikingNo shadeOver grownRocky

What a climb! I highly recommend this trail. This trail really is a two part trail. The first two miles are difficult and will take a lot of time. Once you hit the second mile, the rest of the hike is fairly easy, as it is less steep the rest of the way. Started at 6:30 a.m. to beat the heat since there isn’t much shade anywhere. Bring lots of water. Saw lots of people as I was descending that didn’t have water. Don’t take this trail lightly! Trekking polls will help both ways. The view is like no other! Also, there is a new notebook for signing at the top! Roughly 2.5 hours to the top, and 3 hours and 44 minutes round trip for me today.

View Brandon's Recording
Miguel Hernandez
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarGray StarGray StarSat May 23 2020
HikingOver grownRockyScramble

First two miles are steep and tough. It becomes gradually easier the rest of the way. Bring some poles for the decent. Great workout!!

View Miguel's Recording
Madi Thurston
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarSun May 17 2020
HikingRocky

Last part of the grand slam and it’s a grand finale for sure! The first two miles are straight uphill and will test you but after that it’s just great views! Took 5 hours for my friend and I to complete it including breaks. Beautiful wildflowers right now and not too busy. Great hike!

Gmanju101 .
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarMon May 11 2020
HikingNo shade

Completed the the hike on 5/7/20 weather was in the 60s, round trip took about 4 and a half hours. Did this with 2 of my friends and we all agreed that the hike wasn't as difficult as we anticipated until the very last 30 minutes. The very last 2 miles downhill were pretty brutal and with our fast down hill pace felt like my legs were close to giving out, knees took a serious beating as well. Overall great trip, trail is easy to find. Unlike some other reviews we only drank 1.5L of water each but keep in mind the weather was in the 60s and we are all late 20s and in pretty good shape.

Ross + Barb Borden
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarMon May 11 2020
Hiking

The trailhead is slightly more than 13 miles after turning off Highway 21, a fair distance / miles above Arrowrock Dam. Watch your odometer and you’ll see the trail heading pretty much straight up on your left. There is no signage (that we noticed anyway) other than the Forest Service road number. Good parking available. Legit hike. Do not underestimate. Totally worth it. Trekking poles highly recommended. Completed our Grand Slam.

Rick Roby
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarSun May 10 2020
HikingNo shade

Read all the reviews. Of the grand slams this is nothing like the others. Very difficult. Views are worth it and incredible, but you definitely have to earn it. Our group of 4 went on a day that was high 80’s. I would recommend not doing that. All of us went through our water super early and this hike is hard enough without other issues like dehydration. Recommend leaving as early in the morning as possible. All 4 of us fell down at least once on the downhill back. It’s pretty tricky. While you can tell the path was a little over grown probably a few weeks ago the traffic has made the path super easy to follow. Research the elevation change and trail before you go. It’s long and grueling and nearly the entire hike has significant elevation change. Probably needed to be in better shape. Got a little scary at times as fatigue set in and fairly fit people were struggling as well. Went on Saturday and there was a good amount of traffic, maybe 10 other groups on the trail.

Tink Hammar
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarTue Apr 28 2020
HikingRocky

I love this hike. I love its aggressiveness. The day we hiked was superb weather. This is not a hot weather hike, so plan early departure as warm weather comes on. We encountered a couple of snow patches, but no resulting detours. The trail is pretty identifiable if you take a map for general bearing. We also found a "napping tree" about 1 mi. from the summit that was soft and shaded. From there we hung our packs, took water, map and sunscreen, then hit the summit and back. Will someone headed to the summit in the next few weeks please take another tiny spiral notebook to log names of all who make it? The current little notebook is filling up. I've attached photos of the hundreds of lady bugs that we met among the rocks at the summit. I wanted to scoop up a bunch to bring back with me to my own roses, but alas, left them to their happy mountain home.

Caleb Reimer
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarMon Apr 27 2020
HikingNo shadeRocky

Trail completed 4/25/20. ~5 hours round trip with a few snack breaks. 2 watches both recorded 10.3 miles and 4200 feet of climb. Minimal shade, water only at the bottom. I’d recommend bringing 3+ liters on a warm day. We saw about 10 other people total on the hike. Overall fun trail, will definitely do again. Drive: From downtown boise it’s about a 30 miles / 1hr drive. Last half hour on a pretty decent gravel road. Sedans can make it in good weather with no problems. Trailhead is a little camp ground with a decent amount of parking; should be no issue. Trail: First (and last) 2 miles of the out & back are steep and have some loose gravel/rocks in spots. 2000 feet of climb. Middle 6 miles are about half as steep with no real difficult spots, but very minimal shade. View from the top is worth the work. Trekking poles are a big plus but not essential. Definitely the hardest of the 4 popular peaks. Shaw is about 25% less effort, Kepros about 40% and cervidae 50%.

Rochelle Sorenson
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarMon Apr 20 2020
HikingNo shadeSnow

There were a few north-facing sections left of packed snow. Wear good hiking boots (with gaiters) and you'll make it. I highly recommend trekking poles, sunscreen, and plenty of water. The first two miles are the steepest, but hang in there! The view from the peak is lovely! You may briefly lose the trail, but it's fairly easy to find again. For reference: I'm a very experienced hiker, in great shape, and this is not easy. Many people turn around before reaching the top. Time up: 2hrs 15min, Time down: 1hr 51 min

Zack Autin
Yellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarYellow StarSun Apr 19 2020
HikingNo shadeOff trailSnow

This was my 2nd attempt to bag this peak. Most of the reviews on here are not helpful. The other review from today is from a gentleman who turned around 1/2 a mile in. Hopefully this review clears up some of the unknowns for anyone trying to complete the hardest summit of the grand slams. This review comes from someone in relatively good shape (run trails 20ish miles and mountain bike 20ish miles per week) This hike is no joke. I would break the hike up into 3 phases. Phase 1 - Legs on fire. The first 2 miles of this hike are brutally steep, but it doesn't get a whole lot easier after that point. I can't stress the importance of trekking poles enough for this hike. Phase 2 - False confidence. The next mile is the easiest part of the hike. The trails is up and down, hard to find in some spots but if you just look a few hundred feet ahead you can usually find the trail. Phase 3 - Ridge. Once you make it up to the ridge, you will encounter many false summits. As of April 18, there is 1-2 feet of snow on the North face of each summit. The snow is hard pack and snow shoes are not necessary. We had microspikes and they did the trick. Whoever was on the trail the day before apparently slid down the snow on their butts. It is very steep. I would not recommend it without crampons/microspikes. Grand total it took us 6 hours and 44 minutes of moving time. Gaia recorded 9.5 miles and 3,350 ft elevation gain. We had the summit to ourselves for 1.5 hours. Saw 1 other couple that I'm assuming completed the summit as they were very close. Everyone else turned around before the first 2 miles. Coming down the steep grade at the end is probably the hardest part. Trekking Poles...

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