I was able to get 2 of my 4 lots reduced 4 years ago when they did the last assesment. You have to show comps from similar properties that have sold recently that have sold for less than what they say your's is worth, I had over 12 comps that were all 50-80% lower than mine. I just found solds on Zillow, looked them up on the GIS and gave them a list. They only give you a 30 day window to appeal. Most appeals get denied.
I have 4 extra adjoining lots to my property. Two are 1/2 acre and two are one acre lots. In 2022 they said every lot around here from .25 to almost 2 acres was magically worth 50-55K. They reduced both my 1 acre lots to 27ish and left the 1/2 acre lots at 50. New assesment just added 20K to each one. I'll be going to a lawyer to have all my plots combined into one to see what that does. At least then I'll only have one property to get calls from "investors" about.