Need advice with colorado tree responsibilities and property lines! Citu claims no responsibility

There is a large tree right on the border the property line between the county land and the residence. Both sides have a significant portion of the trunk and branches.

The city is demanding the tree be removed at cost at the expense of the residential owner and threatening to fine otherwise.

I have not been able to find clear information on who is responsible for what and would greatly appreciate any guidance on next steps as the ordinances they cited only mention maintenance but nothing about shared or encroaching trees.

Location is jeffco/lakewood CO BTW. They pulled a similar stunt with trying to fine for the weeds in the area owned by them behind the residence but have since taken care of them themselves.

Thank you!