I am fairly certain all of these are the same plant, and it's in the Apiaceae. My first inclination is either Sium or Cicuta. The side veins of the leaflets end between the teeth (in the notch) instead of the tooth's tip, so that pushes it to Cicuta. Of Cicuta maculata and Cicuta virosa, it's not likely the latter as the Alberta Biodiversity Monitoring Institute only records Cicuta virosa as occurring in northern Alberta so far. That would make it one of the most poisonous plants in North America. To confirm the ID, I'd want to see if some of the lower leaves are multiple-pinnate and/or large air pockets inside the tissue where the stem and root meet.
