Maybe it's the cities' vicinity to one another. Maybe it's that neither team has won a Stanley Cup in over 30 years. Either way the Calgary Flames and Edmonton Oilers straight up despise each other.
On February 1st, 2020 the rivalry boiled over with Cam Talbot fighting Mike Smith at center ice. Talbot got a few shots in, but Mike Smith threw some haymakers and I'd say was the clear winner of this tilt.
I'm sure everyone in Alberta creamed their pants over this one, and the rivalry has only gotten better.