[OR] [SFH] Does HOA have the right to put sign on easement on our property?

My HOA has placed a sign on the easement that runs through our property. They put it right in my front yard and it makes my yard look like a toxic site (see pic). The easement wording does not mention anything about the HOA being allowed to post signs on the easement. The easement is simply for residents to walk along a water feature and for maintenance of the water feature. They say they won't take it down for liability reasons, even though they put a bunch of the signs in the common area. And the toxic weeds are all over our city - never heard of anyone dying from them. Anyway...do I have any recourse to have this removed? They are refusing.

https://preview.redd.it/mdrkasoos91g1.jpg?width=4032&format=pjpg&auto=webp&s=02810cca5bcb1f86edfc8ee3183ece0de9aa7901