This is an extended version of a comment I left on a link after it was revealed that morgan would be the crossover character between TWD & FTWD.
I'm not all that enthusiastic about the idea, but it is technically possible ibingiay the two timelines. The way I see it, it could go down one of three ways. But first, a look at what happened when with Morgan:
-Day 60: morgan and his son Duane met Rick in King County, Georgia.
-Day 314: morgan met Rick again in the same town. Duane is gone, and morgan has set up all kinds of walker (and human) traps in town.