Many people were upset when Lancaster, NY took down their assessment challenge web site. The site referred to as OARS (online assessment review system) was helpful in finding comparables for your house and providing you with other homes in your area.

In addition to that, it was useful for local real estate investors when searching for a property in Lancaster. The profiles include quite a bit of detailed information regarding a property and also includes a picture of the property.

The system is back online. It might not be the easiest thing to find, so here is the link:
Lancaster, NY online assessment

Good luck.