That sucks. I’ve seen similar and larger increases over the last 2-3 years. The county keeps severely upping my assessed value. I’ve contested the valuation twice with fair success the first time but the 2nd time, when I was much more correct than they were, they just blew me off and claimed they were right. Ever since Colorado voted in TABOR (taxpayer bill of rights) capping increases and forcing them to return extra revenue, they have gotten extremely overzealous with their valuations.
Curious, are your increases due to valuation or increasing tax rates and mill levies?