Mauna Loa Bike Climb - PJAMM Cycling

62.2 mi
11,874 ft
3.4 %


Page Contributor(s): Ron Hawks, Las Vegas, NV, USA Ties Arts, Bussum, Netherlands; Luke Hise, Phoenix, AZ, USA


Mauna Loa is one of the only bike climbs in the world where you can say, "I did the __________ bike climb in the world."  Mauna Loa is hands down the longest bike climb in the world and is a grueling climb from nearly sea level to 11,000' above sea level. Mauna Loa can also be accessed from the opposite side of the Island of Hawaii from our western approach, but starting from the east will not put The Longest Bike Climb in the World into your trophy case. After turning onto Mauna Loa Observatory Road at mile 45 (with 17 more miles to climb) you are surrounded by landscape like no other on any climb we have ever done - if you want to know what it would be like to ride your bike on Mars, climb Mauna Loa. 

See also our Mauna Loa Hike page and our dear friend Erwan Treguier's entertaining tale of Mauna Kea + Mauna Loa . . . in the same day!
Do not be lulled into complacency by the mundane 3.4% average grade for the Mauna Loa bike climb.  First, you are climbing for over 50 miles which is a grind like no other.  Second, there are several descents which when removed increase the true average grade from 3.4% to 4.2%.  Third, you are climbing at altitude, finishing at an altitude with 33% less oxygen than where you began at sea level. 

The steepest quarter mile of the Mauna Loa bike climb is 11% and steepest mile is 8.8%.  The final 3,000' feet of altitude gained (10 miles) is at 5.6%.  The only "good" news to be gleaned from the stats is that less than 2% of the climb is 10%+.

See more details and tools regarding this climb's grade via the “Profile Tool” button.
Observatory Road is closed at Hwy 200 as of November 28, 2022 due to Mauna Loa eruption and lava.

Roadway:  Excellent condition for the entire climb.

Traffic:  This is a problem.  The first 19 miles on Waikoloa Road and Highway 190 have moderate to heavy traffic, including commercial trucks, traveling at 50-60 mph.  However, there is a wide shoulder those first 19 miles.   11.5 miles on Old Saddle Road are a blast with minimal traffic.  Onto Highway 200 (Saddle Road) for 13 miles of busy and fast moving traffic, but with a wide shoulder with rumble strips separating slow lane from shoulder. Once onto Mauna Kea Access Road (final 17 miles) vehicles are rarely encountered.

Parking:  This is hard to find near the start.  We park on Waikoloa Road just past Highway 19 and ride 3 miles down to the climb's start.  MapStreet View.
Cothing:  I have been snowed on (in December) on Mauna Loa.  Consult the PJAMM Weather Tool for the forecast at the time you expect to finish your climb and bring or stash appropriate gear. 

Provisions:  As of May 2018, the only place after Waikoloa Village (mile 8) for provisions on this 62 mile route are the vending machines (water, Gatorade, chips, and candy bars) at the Gilbert Kahele Recreation Park at mile 38.5 - Map Street View.  I would not rely on those machines being there when you go, though.  I have stashed provisions at the beginning of Mauna Loa Observatory Road (and Mauna Kea Access Road when I've done that one) in the past.
Before heading out on any cycling adventure check out our Things to Bring on a Cycling Trip and use our interactive check list to ensure you don't forget anything.
VRBOs for cycling Mauna Loa
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We prefer staying in the Kailua-Kona (25 miles south of climb start) area as it has a more low-key (and reasonable) atmosphere which is to our preference (and, hey, Kona Brewery).  The Hilton Waikoloa Village area closer to the climb start has higher-end accommodations, and we have stayed there, but we got a great deal! 

Also consider climbing Mauna Kea (hardest bike climb in the world), Kaloko Dr (US #5 hardest bike climb), and Waipio Road (steepest mile road in the world). 



Difficulty: Strenuous



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Jan 9, 2023
A truly epic ride, we parked at Cindercone carpark on the Saddle Road and then descended to the pacific shoreline in Hilo and turned round and rode back to the carpark for a feed/drink stop and then onward to the Observatory, we were working there so had access through the gate beyond the top of the official climb! The descent back to the car was as the sun went down and at that altitude it gets cold pretty quickly. The road down was like being on a kids toy racetrack! Super Kudos to my ride buddy (she has the QOM) for the day on a fairly clunky hired bike and later discovered she was pregnant!!! 💪💪💪 Of course this road is no longer passable since the recent erruption at the end of 2022!
Sep 23, 2022
difficulty: Strenuous
scenery: 4
traffic: 5
road: 4
Sep 23, 2022
scenery: 4
traffic: 5
road: 4
Rode unsupported from Hilo. Stashed water and energy bars every 10 miles. Hid my water at the beginning of the obervatory road so well I couldn't find it until I came back to collect the bottles. Kaumana Dr and Saddle Rd are easy going climbing. It was overcast so really didn't get much views apart from the first section of the observatory road before heading back into the clouds. It gets challenging above 9000ft on the steep pitches and altitude. Toward the end I felt disheartened to look back at what looks like a fairly long way home back over the ramps. Don't worry, the moment you turn around it's a roller coaster ride all the way back to the Saddle. Well worth the slog!
Jul 23, 2022
difficulty: Extreme
scenery: 5
traffic: 5
road: 5
Jul 23, 2022
scenery: 5
traffic: 5
road: 5
This is a very challenging climb. I’ve done a number of the higher FIETS rated climbs and they don’t come close to how tough this is. My support guy said it’s generally between a 6-9 hour climb for most people. Mauna Loa is relentless and has basically no descent more than a couple minutes long over the entire climb. The whole last 15 miles or so are rollers with steep pitches touching up to 18% (as measured on my Hammerhead). Combine all that with extreme altitude and in my mind, you have an extreme climb.
Jul 19, 2021
difficulty: Extreme
scenery: 4
traffic: 5
road: 5
Jul 19, 2021
scenery: 4
traffic: 5
road: 5
It’s possible to do this ride alone if you plan ahead. There was no longer a vending machine at the Gilbert Kahele park as mentioned. 1 strategy is to “stash” drinks along the way in advance (just remember which mile marker you leave them at & don’t be a jerk- take your trash with you or make sure you drive back to retrieve it). If you ride from sea level, you’ll have some traffic, which gradually drops off the further you climb. When I did this ride 03/2021, I saw only 1 other cyclist & less than 5 cars on the M. Loa observatory road in all the hours it took me. The weather is unpredictable. I was met by sleet near the top. The scenery is unique, but on a cloudy day, the observatory road became quickly tedious, with nothing but lava fields and no birds or animals for hours. The constant little up & downs can be a battle as mentioned. The air is thin and myHR showed it. It’s not a steady climb you can just put your head down for & zone out to. But at least the roads are smooth!
Jul 16, 2021
difficulty: Challenging
scenery: 5
traffic: 5
road: 5
Jul 16, 2021
scenery: 5
traffic: 5
road: 5
Rode this 7/7/21 starting from Inouye Hwy. The road has been repaved and is perfect, unlike what you see in older pix and google maps. It's a perfect morning ride when you don't have time for an all-day ordeal/thing. Go early so the heat doesn't get you and 2 bottles will be enough. You may start in some fog but will climb clear by 7000ft. The views are absolutely the best: Hilo under clouds to the east, giant Mauna Loa shield that you are climbing to the south and west, Mauna Kea/Kohala/Haleakala to the north. Only traffic was a few work vehicles headed up to the observatory construction site. It's a stunningly scenic climb. Descent is fun but extra caution in the rollers where you cannot see far ahead. You are likely to encounter at least 1-2 vehicles coming up and there is no bail out - it's either into the lava field or a head-on.
May 21, 2021
I agree with the above that this climb is much harder than the math suggests - the little dips and kickers aren't captured in the contours, but they get really draining. Very hard to get in a rhythm. Also, important note: on 5/20/21, there are NO vending machines anymore at the rest stop on saddle road, so you'll need to carry all your food. The maintenance guy didn't know if there was a plan to bring them back. There is ample water, however. Coming from Kona-Kailua, you're looking at about 120 miles between services, R/T.
Apr 25, 2021
difficulty: Extreme
scenery: 5
traffic: 5
road: 4
Apr 25, 2021
scenery: 5
traffic: 5
road: 4
This climb is much more difficult than the modest gradients suggest. The Saddle Road is smooth with even grades. But, the Mauna Loa Observatory road just follows the contours of the lava fields. There are dozens of 11-14% ramps for 10-50 pedal strokes, followed by short flat or even downhill sections. So, while the grade might be only 6-7% over 1/2 a mile, you will be expending a lot of energy on those ramps. These would be tiring at sea level, but are really felt above 8,000 feet. That said, the downhill 17 miles back to the Saddle Road is the most exhilarating descent I can remember. You start to approach 35 mph, then go up a ramp to scrub some speed. We saw only three cars in three hours. But, it's a one lane road with some blind corners, so keep to the right so you don't get surprised (or worse). Headwinds can be an issue on the descent as well. Check National Weather Service and do pinpoint forecasts before you set out. There are no services. Traffic rating is for MaunaLoa
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Cycling Mauna Loa

Ride 62.2 miles (world’s longest climb) gaining 11,848’ at 3.4% (4.2% climb only)

WARNING AS OF JANUARY 9, 2023:  Observatory Road is closed due to lava flow.

Photo of Mauna Loa from Mauna Kea Visitor Information Center

Keith Kefford (photo circa late December, 2022)

Photo Keith Kefford

The road will open when it is safe - unknown time as of January 9, 2023

Input from Keith regarding Mauna Loa Observatory Road as of January 9, 2023:

It will probably be a while before the road is open again to regular traffic. The lava crossed it in two places and the flows are pretty wide. It's a pity because it was a fantastic climb and a great descent. They will be working on getting it open to some degree as the Observatories at the end of the road need access. As of now the road is gated off at the junction with the Saddle Road Highway.

Mauna Loa - the longest bike climb in the world

US Top 10 Most Epic Bike Climb

Climb summary of PJAMM’s John Johnson.

Ride 62 miles up, up, up . . . .

Photo:  Saddle Road on right; Mauna Loa Access road lower right to center

Aerial photo shows the entire shield volcano at sunrise.

Rarely do we have the good fortune of exclaiming “This is the _________climb in the world.”  There is only one hardest (Mauna Kea), one highest (Uturuncu), one most deadly (Death Road), and one LONGEST (Mauna Loa) in the entire world.


What good fortune we have that the hardest AND longest roads in the world are on the same Island (Hawaii’s Big Island).  At 62.2 miles, Mauna Loa is a good distance in front of the world’s second longest climb, Wuling Pass East, Taiwan  (54.3 miles).

Cycling Wuling Pass East - Taroko Gorge, Liwu River, marble walls, roadway

World’s #2 longest bike climb - Wuling Pass East, Taiwan

Surprisingly, of the two routes to the top of Mauna Loa, the longest route is also the lower ranked, coming in at #8 US/#101 World, versus the shorter at 44.8 miles which would rank #4 US/#33 World (MAP).

PJAMM May 2018 Great Hawaiian Adventure Blog and Trip Page.

Before heading to Hawaii for your Mauna Loa cycling adventure, be sure to rely on our list of Things to Bring on a Cycling Trip, and use our interactive checklist to ensure you don't forget anything.

When to Climb Mauna Loa

PJAMM Cycling has taken on Mauna Loa once in May, twice in June, and once in December (we had to call in for help on that one as we got caught in a snowstorm at the top).  The lowest rainfall months on the Big Island on the eastern side (Hilo) are May and June and the highest rainfall months are March, April, and November. Thus, we recommend cycling the Hilo side in May and June.  The lowest rainfall totals on the western side (Kona) are February and December.  We have no data for the top of the volcano and in our experience it is best to climb in May and June.  The temperature throughout the year consistently averages in the 70s at sea level, meaning it’ll always be warm in Waikoloa when you start, but often cold at the top (it was in the 30s and snowing in December 2013 when we rode to the top).

Climbing Mauna Loa by bike - Mauna Loa Observatory Road - roadway and telephone poles with lava field

The weather can change in an instant on the volcano.

How to Climb Mauna Loa by Bike

While this climb is not as “hard” as its neighbor Mauna Kea, it is by far the longest bike climb in the world -- 124 miles round trip.  Train very seriously for this climb. The climb begins in Waikoloa Hilton Village by riding east (and yes, uphill) on Waikoloa Beach Drive, across Queen Ka’ahumanu Highway (mile three) then on up Waikoloa Road. We rise to 11,000’ so it is best to altitude train if at all possible.  Our training has only consisted of cycling up 10,000’ to Haleakala in Maui, before flying to the Big Island to climb Mauna Loa in preparation for Mauna Kea.  Since studies suggest it takes three weeks to become fully acclimated, unless you’re planning on an extended vacation, you’ll probably just have to suck it up and go for it without much altitude preparation.

Climbing Mauna Loa by bike - Mauna Kea Park - flags and visitor center 

Mauna Kea Park -- mile 38.5.

Bicycle ride of Mauna Loa - Mauna Kea park vending machines and provisions.

The only spot on the climb where provisions can be had. 

The first segment from start to the right turn onto Mauna Loa Observatory Road is 44.6 miles, 3.2% average grade and gains 7,318’ over that distance.

Sea level to 11,000’ in 62 miles . . .

 Start of climb -- Hilton Waikoloa Village (elevation is two feet here).

Waikoloa Road to Hwy 190 (15 miles) + Hwy 190 to Old Saddle Road (5 miles)

Cimbing Mauna Loa Volcano by bike - cyclists on old saddle road with cinder cone in background

Climb Old Saddle Road for 11 miles (gain 3,095’/descend 191’).


Old Saddle Road.

Bike climb Mauna Loa - Cyclist on Hwy 200 - Saddle Road

14 miles on new Highway 200 (Saddle Road) at 1.5% average grade.

At the 44.8 mile mark, turn right onto Mauna Loa Access Road and climb the final stretch to the Mauna Loa Observatory -- 17.5 miles, 4,457' climb, 17' descent with a 5.2% average grade.  This stretch of road is desolate, with very little traffic.

Bicycling Mauna Loa Volcano - turn off sign to Observatory Road

 Mile 45.

Mauna Loa as seen from Saddle Road (bottom middle) and Observatory Road (other 3 photos)

Cycling Mauna Loa Volcano - roadway, lava field and roadway sign

Road ends at the observatory -- not a through road.

Cycling Mauna Loa Volcano - roadway, lava field and roadway sign

Beware of fast changing weather, colder temperatures at the top and the effects of altitude.

The moonscape of Mauna Loa Volcano.

If you get onto the volcano early, you just never know . . .

The road is unique - it does not appeared to be engineered or graded level - it is all rollers from start to finish, as if the road creator just scraped off the lava and poured pavement without concern for standard road design engineering protocols.

Geo marker mile 49 (4 miles after turning off Saddle Road)

Photo left is Mauna Loa in background and photo right Mauna Kea.

Bicycle climb Mauna Loa Volcano - Bruce Hamilton and Stacy Topping cyclists at Mauna Loa Observatory with bikes

Stacy and Bruce at the finish -- Mauna Loa Observatory in the background.

The one lane Observatory Road has been resurfaced as of 2013 and is in much better condition than its former decrepit state.  Of all the climbs you will ever do, this one will give you the feeling of being on the moon more than any other.  The lava fields range from smooth lava to basalt-looking rock that stretch for thousands of acres.  There is little to no vegetation along this route -- it is all lava with not only no green, but also not a bit of vegetation anywhere to be seen for miles.

Cycling Mauna Loa Observatory Road in poor condition 2011   

 Roadway in 2011 before it was repaved - quite the adventure!


Bicycling longest road in the world - Mauna Loa Volcano - undulating roadway

Mauna Loa Observatory Road is all about rollers.

View of Mauna Loa shield volcano from distance

After travelling 45 miles and turning onto the final leg, we still have a ways to go.

17.5 miles, 4,457' climb, 17' descent with a 5.2% average grade.

Climbing by bike Mauna Loa Volcano - cyclist climbing steep section of Mauna Loa Observatory Road

Although the climb averages 5.2% for the final 17.5 miles . . .

There are plenty of steep pitches.


  • CChristian James (also exceptional photographer) can be hired to SAG and photograph your momentous ride.  Phone (440) 225-9807, email: and website here.

Chris, John and Jen after our May 24, 2022 Mauna Kea climb.

  • PJAMM founder John Johnson’s personal note and endorsement:  Chris and Jen SAGed for us on our 2022 Mauna Kea climb and they were absolutely INVALUABLE, pleasant, fun, competent, enthusiastic and supportive.  They have supported cyclists many times on the Mauna Kea climb and other cycling climbs and rides on the Big Island  and know exactly where to stop for support and for photographs.  Many of Christian’s exceptional photographs appear on the Mauna Kea page, including the Featured Image.  If you are in need of SAG while cycling the Island of Hawaii, we highlyrecommend using Chris and Jen.


In our experience, the weather is better earlier in the day than later.  The most epic part of the climb (other than it being the longest in the world) is the last 17 miles: riding over the volcano moonscape on a narrow road with no traffic, passing by surreal telephone poles in site of the mighty Mauna Kea to the north.  The descent over the 17 miles of Observatory Road is equally unique and exhilarating.  Thus, if you’re short on time or don’t feel like you’ve trained enough, leaving in the early morning and just doing the 17 miles is an attractive alternative to the full ride.

Mauna Loa Access Road - 8,500’ - 8 miles to finish.

Snow Capped Mauna Kea in background.

Mauna Loa as seen from the top of Mauna Kea during winter.

The roadway from Waikoloa to the Mauna Loa Access Road is busy, particularly the start to mile 17 (turn off to Old Saddle Road/Highway 200) and then from mile 27.7 (back on main Highway 200) to the turnoff to Mauna Loa Observatory Road.  The remainder of the trip is quite the opposite of the first part; in our three trips up Mauna Loa Observatory Road we have seen no more than five cars - TOTAL!  Beware that there are absolutely no provisions or water available for the last 54 miles of this climb.  

Mauna Loa as seen from Mauna Kea -

views are to the south from Mauna Kea.

Left photo is from the gravel; 3 other photos are from near the top of MK.

The road from Hilo to Mauna Loa Access Road is busy and the traffic travels at a highway clip.  However, there are deep rumble strips separating the wide bike lane from the roadway for much of Saddle Road, and while the traffic can be a bit unnerving, for a highway this is a medium risk route.  In my six trips up Mauna Loa and Mauna Kea, I have never experienced a close call.  

Mauna Kea as seen from Mauna Loa.

Views are north to Mauna Kea from Mauna Loa.

The weather will be nice in Waikoloa or Hilo any time of the year you start.  However, also beware that 11,400’ up the volcano, weather conditions can change dramatically.  In December 2013, we left Waikoloa in 75 degree weather only to run into snow near the top of the climb.

Video is taken on Mauna Loa - Mauna Kea is in the background.

A Bit About the Mauna Loa Observatory

Built in the 1950s, the Mauna Loa Observatory (MLO) has been “monitoring and collecting data relating to atmospheric change, and is known especially for the continuous monitoring of atmospheric carbon dioxide” since 1958 as part of the National Oceanic and Atmospheric Administration.  This observatory is the oldest continuous CO2 monitoring station in the world, and is the “world's primary benchmark site for measurement of the gas” (Wikipedia).  Because the conditions of “undisturbed air, remote location, and minimal influences of vegetation and human activity” the MLO is an ideal location for monitoring atmospheric factors that can cause climate change (Mauna Loa, Hawaii Observatory).

Mauna Kea left and Mauna Loa to right of photo.

Photo taken on Waikoloa Road - 55 miles from the volcanos.

Visiting Mauna Loa

The Mauna Loa volcano is part of Hawaii Volcanoes National Park.  More information about visiting and camping in the area can be found on the National Parks Service website.  Note that due to the May 2018 eruption of the Kīlauea volcano, areas of this National Park are still in recovery (read more about the park’s recovery process in this article from the National Parks Service).  Though it is an active shield volcano, Mauna Loa itself has not erupted since April 15, 1984.

Mauna Kea to the north, 10 miles up Observatory Road (seven miles from top; 8,000’).


“Mauna Loa is simply a giant climb and one of the most difficult in the world. After 1.2 miles in town turn left on Kaumana Road (which becomes Saddle Road). Rolling miles follow and signs of civilization (including most of the traffic) soon end. Lava eventually replaces trees as you ride between two massive volcanoes over a moderate and rolling grade...Soon the grade eases within the saddle between mountains with very long views in places. At mile 27.7 turn left on an unmarked and narrow road.

The first 4 miles or so of this section of pavement are excellent; having been recently repaved since my frist visit up the mountain. The remainder of the route is poorer asphalt but still rideable. The grade is fairly shallow down low but tends to gradually increase as you ride. The landscape is lunar like as you ride the narrow strip between massive files of black lava. The last stretch of climbing contains some steeper pitches, particularly within some turns and debris at times on the road surface. Great views of the lunar-like landscape are your only company up here besides elevation markes painted on the roadway every 1000 feet. Near the top you hit some steeper grade and poorer pavement in places (along with big views) and the climb eventually ends at a weather station above 11,000 feet.

Keep in mind most of this last stretch from Saddle Road is isolated and not maintained. There is an old track (mountain bike/feet only) at the end of the road that leads to the very top of Mauna Loa. It’s descent is challenging on top and fast in places down low. This is one of the greatest continuous elevation-gain paved road hill climbs on earth and as mentioned its final section is quite isolated so go prepared before you head for the top of this one.” (This quote is presented with the approval of John Summerson, from his book, The Complete Guide to Climbing (by Bike), 2nd Edition, pg. 180.)


In addition to 2 solo trips, I have had the great fortune of climbing Mauna Kea with good friends three times.  The most recent (hopefully not final) time was in 2022 with, among others, my dear friend, comedian, great story teller and really fun guy, Erwan Tregiuer from Brittany, France. This is a link to one of Erwans great stories and adventures (Mauna Kea and Mauna Loa in the same day!! - Erwan’s Great Adventure)

These two volcanoes , so close and certainly "magmatic blood brothers" 🌋🌋 at almost identical altitudes, are different in many ways. Big Island, so "big" that its weight causes the oceanic crust to bend up to several hundred km, is made up of several volcanoes, the highest being Mauna Kea (MK: 4207m) and Mauna Loa (ML: 4169m). Let us mention in passing the dates of their last eruptions at the time of this release: -2500 for the MK, 1984 for the ML (see footnote for a small update!). The ML is more massive (it is the heart of the Big Island) and represents the archetypal shield volcano, crowned by a cyclopean caldera (like its even more colossal Martian cousin, Olympus Mons ). From a distance, its slopes seem regular, moderate and smooth, while the MK is steeper and more irregular, bristling with a large number of secondary cones (it would be in a later eruptive phase). Up close, they are also different: the ML appears to be formed by an accumulation of solidified lava flows, while the MK rather evokes a monumental pile of ejecta of various sizes and colors, ranging from ashes to large volcanic bombs. Even their rocks seem to have quite distinct compositional signatures (related to a bifid mantle plume ?). 🔥🔥 In short, the origin of these differences seems to give scientists a hard time, but it's not just the mountain that changes: the roadAlso! While the MK's road seems to have been forcibly dug to climb the mountain, which it cuts with a brutal and mercilessly steep route offering not the slightest respite, that of the ML, thinner, resembles a ribbon of asphalt delicately placed on the lava fields that stretch as far as the eye can see, marrying the undulations of the landscape, which gives the impression of evolving on a roller coaster, 🎢 according to the many small descents that intersect the climb! The huge asperities of the lava make us feel very small, as does the majestic and imposing silhouette of the MK, which dominates the landscape (a few hours earlier, the roles were reversed!). We feel even more isolated from the world, in this chaotic landscape which corresponds to the idea that

That’s a wrap!!