It's more of a bike trail, but I've seen people running on it too, but the Wasatch Crest Trail is one of my favorite trails in all of SLC. I always started (with my bike) at Guardsman's Pass, but you could always start from City Creek. It would be a hell of a long run, but I have never seen better views anywhere in the SLC area.
Of course, with all the snow you guys got this year, the trail might still be covered in snow.
Pics included: