My 10 Most Difficult Marathons

I just finished the Jackal Marathons.  Those were among the toughest marathons I’ve run, so it seems like this is a good time to compile a list of my most difficult marathons.

A lot of different factors can make a race difficult.  Some are difficult because of the elevation or the amount of climbing.  Others are difficult because of extreme weather conditions.  I personally find trail marathons to be more difficult than road marathons, if I have to worry about tripping on rocks or roots.  Finally, racing on consecutive days is always tougher than racing with fresh legs.

One way to take all those factors into account to rank races according to how long it took me to finish.  That’s what I’m doing here.  The following is a list of my 10 slowest marathons, followed by the factors that made them difficult.  I’m not considering ultramarathons.  I also omitted one race where I was just taking it easy.  In these races, I was really trying.

Race:  2025 Native Jackal Trail Marathon

Time:  8:17:41

This was the fifth race in a five-day series.  Every race in that series saw the heat index climb above 100 degrees while I was running, and it took a cumulative toll on me.  This race was the hottest of the series, with the heat index hitting 109 while I was still running.  Adding to the difficulty, it was mostly on trails, and there were numerous steep climbs.  I had sweat streaming out of every pore, and I was so exhausted by the end that I sometimes had to stop to catch my breath after each step up on the steeper climbs.

Race:  2026 Native Jackal Trail Marathon

Time:  7:50:01

This was the same race a year later.  The factors that make this race difficult were all still there.  I was faster this year only because it wasn’t quite as hot.  The temperature peaked in the low 90s, with a heat index in the upper 90s.  I was still on the course at the hottest hour of the day.

Race:  2026 Backass Jackal Trail Marathon

Time:  7:27:19

This was a trail race on a hot day.  It was the second day of a series, so I was already tired from running the same course the day before, when it was extremely hot.  What made this race more difficult than usual was a thunderstorm and the subsequent deterioration of the course.  It rained hard for almost an hour.  By the time the rain was done, the trails were filled with water.  As the day progressed, the trails got increasingly muddy.  It was difficult to get any traction going up hills.  Going downhill was scary, because I couldn’t control my momentum.  At any time, one of my feet might go sideways.  I slipped and fell in the mud numerous times.

Race:  2017 Moose Mountain Marathon

Time:  7:18:45

This is a technical trail race.  It’s the last 26.2 miles of the course for the Superior Sawtooth 100.  What made it particularly difficult for me if that it was literally my first run in more than 12 weeks.  Earlier in the summer, I had back surgery, and I wasn’t allowed to run while I was recovering.  I took up race-walking so I could still do marathons.  I had been doing tons of walking, but no running.  I could walk fast on a road course, but not on technical trails.  On race day, I did a mix of about 40% running and 60% walking, after doing no running in training.

Race:  2026 Icefjord Midnight Marathon

Time:  6:51:37

This race was about one third trails and two third roads.  The trail sections were over uneven rocky terrain with some steep climbs.  Here’s what the trails looked like:

The best runners could actually run these trails, but the best I could manage was to hike those sections.  Even the road portions were difficult.  The biggest hills were on the road sections, and I needed to take walking breaks.

Race:  2026 Jackal Trail Marathon

Time:  6:45:35

This was a trail race.  It was on the same trails as the Backass Jackal Trail Marathon.  I’m always slow on trails, but this race was tough because of the heat and humidity.  The heat index reached 103 by the time I finished.  It was the first day of the Jackal series, but I couldn’t claim to have fresh legs.  Just six days earlier, I ran a 24-hour race in hot humid conditions.

Race:  2025 Backass Jackal Trail Marathon

Time:  6:45:20

This was the second day of the 2025 Jackal Marathons series.  I had tired legs from the day before, and it was the second consecutive day that the heat index climbed above 100 degrees while I was still running.

Race:  2025 Jackal Trail Marathon

Time:  6:27:53

This was the first day of the Jackal Marathon series, so I had fresh legs, but I struggled with the trails and with the extreme heat and humidity.  Like every race of the series that year, the heat index was above 100 degrees.

Race:  2001 Pike’s Peak Marathon

Time:  6:23:07

Several things make this race difficult.  First, the elevation ranges from about 6,300 feet at the start to 14,100 feet at the summit.  In the first half of the race, the air gets thinner and thinner.  In the second half, you’re already intensely out of breath, and it’s hard to catch your breath until you’re done.  Second, the climb is steep.  The average grade is more than 10%.  That’s just an average.  Some parts are close to level, but other parts are much steeper.  Descending isn’t any picnic either.  The steep descent beats up your legs.  Finally, it’s a trail race.  At the lower elevations, it’s dirt or gravel.  Above the tree line, it’s rocky.

I don’t live in the mountains.  I trained for the climbing by doing long treadmill workouts, setting the incline as steep as 15%.  I couldn’t train for the thin air.  I live at a lower elevation, and I didn’t arrive in Colorado until the day before the race.

Race:  2015 Eugene Curnow Trail Marathon

Time:  5:56:11

Technically, this was my 11th slowest marathon.  I skipped one race, because it was a race where I was walking with friends and not caring at all about my time.  In this race, I was doing my best.

This race was on technical trails.  Different sections of the course were challenging in different ways.  Making things worse, I was injured.  I was running this race with a groin strain in my right leg.  It was painful taking big steps uphill, and it was painful descending.  I had to fight like mad to keep my time under six hours.