Some early observations from my trail running and hiking here in Colorado so far...
1. I actually do run into other runners on the trails here, though not as many as I thought I would. In Illinois I believe I saw exactly one runner my whole life aside from the Rockford area parks.
2. Even in Colorado the trail runners are regarded as slightly nuts. One lady who clearly underestimated my hearing commented after I bombed by her and her friend "that is dangerous!" I am choosing to believe she was concerned for MY safety and not afraid I might careen out of control and somehow injure her!
3. Sharing the trails with mountain bikers is not nearly as bad as I thought it would be. In the Midwest it's rare that this happens but here it is the case more often than not. In fact they often outnumber those on foot by quite a lot. However, the bikers are very good about calling out when they are coming up from behind and are really generally super friendly people.
4. The trails here are SO relentlessly technical! Rarely do you get a chance to stride out easy for any amount of time and the downhills take quite a bit of concentration. Running on trails with jagged rocks that are sometimes the size of basketballs takes some getting used to for sure. It's a ton of fun but also pretty mentally exhausting. I have managed to not fall yet, though my toes have taken a pretty good beating.
5. Hydration is very important here. The air is so dry you do not realize how much you are actually sweating because it evaporates so quickly. After my first couple runs here my pee was just about the color off honey. Not good. You really have to drink even if you don't feel thirsty.
6. Be prepared to go up for a long period of time. You can get some pretty good climbing in some Illinois and Wisconsin parks but it's more of an "up for a couple minutes then down for a couple minutes" type thing. Here you can go up for what seems like an eternity. On one of my first runs I went up switchbacks for the first 1.8 miles. It never leveled of once until then. I like hills but, oh boy. Let's just say I have been working on my power hiking during my trail runs here.
7. I have been doing a lot of hiking since I have been here and making sure when I am running that I stop and take in the scenery once in a while. I have always made an effort to do this, since trail running requires that you look down most of the time and it's easy to miss most of the scenery. It's important to stop or walk here and there and appreciate your surroundings. It's a huge part of the experience of running in nature, especially somewhere as stunning as this.