Michels is the name of the company that is doing the actual building of the Keystone XL Pipeline. Michels has offices, subsidiaries, and projects all across the country. A list of them has been compiled and can be found here.
Please consider doing one or more solidarity actions at any of these Michels locations.
For some of the reasons to target the KXL and Tar Sands check out:
Tar Sands Blockade- Why Oppose KXL