Running Groups in Denver (Preferably Near DTC)

Hey all.

I recently moved to Denver and I wanted to ask about running groups that are in the area. I used to run with a team in high school but I didn't keep competing when I went to college. Now that I have graduated and moved to Denver, I have been wanting to find some people to run with. I have seen a few groups through searching online but I was wondering if anyone has had experience with any groups around Denver.

I am also curious how these groups work. How do you join usually? As someone that doesn't often just go out to meet with people I don't know, do you just kind of show up to something like this or is it better to reach out somehow ahead of time?

To elaborate a bit, I think my motivation is more to find people to train with and not just looking for social engagement. Don't get me wrong, the social aspect is important to me. I guess I just am less interested in groups where you do a quick run and spend the rest of the time at a bar or something. I'm not sure if that is common around here but I have seen a lot of groups like that in other cities. I would just really like to find a group of people that are really passionate about running and improving that can help me push myself.

I am near the DTC area personally so I am happy to travel if I need to but I was also curious if there are any groups that meet around here. I haven't seen many in my searching around.