Wow, my mom grew up in the Broadripple area and attended Broadripple High back in the early '50s. That area seems to have gotten a bit rougher.
Anyway, a couple of comments:
The original poster said the situation got off to a bad start because the ranger shined a light in his eyes. The police are trained to do that in order to have the upperhand. If you did have a gun and intended to shoot him, it would be a little more difficult if you were blinded by the light. He's doing his job.
The ranger defined dusk when he said you had to leave. I seriously doubt a local court is going to try to determine whether dusk occurred at 6:01 or 6:04 p.m. They will probably say that the ranger is in charge and if he told you to leave at high noon, you are supposed to leave.
To the guy who wanted to know if he should run if the cops tell them to halt, why be stupid? Running makes it appear that you are doing something wrong. Just be polite and do whatever you are told to do.
My local park also has a dusk to dawn curfew. I've been stopped by the cops dozens of times over the 9 years I've run there. I'm always polite, point out the nearest exit from the park, and ask if I can leave that way. One cop has stopped me so many times that he just calls me by name and asks me to leave. I've never gotten a ticket.
On the other hand, by running at night through that area, I've helped the cops catch people who were doing illegal things. I was running one night and saw some kids selling pot to a bunch of other kids. I kept going and saw two officers sitting in their cars. I asked them if they wanted an easy bust and showed the fastest/easiest way to get to the scene. Ever since then, those two officers just wave at me when I run on the trail at night.
If you're not doing anything wrong, just stop, answer their questions, and move on. They deal with a lot of situations daily that are potentially dangerous to them; there's no reason to set them off just because you want to run to a certain place.