Running it this year, ran it last year in Whistler.
Finished in 3 hrs (they do have a clock at the finish so you can figure out your time if you look at what time you depart at) We ran the majority of the way, most people were walking. I bet 3/4 of the people seemed to be walking or a very slow jog. Like previously said in this thread, people are there for fun and not to race. You run about 1km (4-5 minutes) and then wait/do an obstacle, lots of time to rest up.
Tips:
1) Shoes - Tie your shoelaces good, they will be covered in mud and some places you are waist deep in mud and if your shoe is lose you will lose it in the mud and won't be able to get it back. Saw a couple people running with 1 shoe left.
2) Gloves - Buy a pair of $10 gloves from Rona. You do a lot of crawling and it does a number on your knees and hands. Gloves also help a bit for grip and not getting splinters.
3) Clothing - I wore shorts and a underarmor long sleeve. It worked well. The first obstacle was the artic enema (jumping into a dumpster full or ice, submerging yourself and walking across) so you are soaked the entire race. They make sure you are almost always wet. By the end we were quite cold, they do have thermal blankets that a lot of people are walking / running with.
4) Start times - It doesn't matter what your start time is, just get there and register. Then they call by time and you just walk up and jump into this wooden rectangle. When it fills up they do the speech/cheer and then they let them go. If you don't like your time and want to go early/later just show up then. **It MIGHT not be like this in Drumheller, just giving the Whistler experience**
5) Obstacles - Cold water sucks. Elecricity + Cold water....
From what we experienced on our team, do not take your shirt off right before crawling through the electricity. The electricity really hurts, feels like a good ol punch. Most people cover their faces with their hands and run through it.
Have fun, it's quite the experience. Will be interesting to see how the mud is in Drumheller compared to the mud in whistler.