Yes you can. It's not always easy, but is anything when dealing with tax collecting agencies. With property values in decline, local governments always seem to be a bit slow in reducing the value's. When values on moving up, you'll find governments tend to be johnny on the spot, in making sure their value reflect the current market. It is their income base after all. 

The government factor property values in the same way an appraiser does, just with less precision. Don't expect your new granite counter tops or tile flooring to factor into your assessed value. The accessors office will typically just use comparable sales or COMPS as they are more often referred to, in determining your value. Essentially they will find what your neighbors homes have sold for, determine the $/sq ft. and apply it to the square footage of your home. 

For example a neighboring home a quarter mile from yours sold for $200,000 - it was 2,000 sq/ft. So square footage value was $100/sq ft. Your house is 1750 sq/ft, so using the same valuation method your house would be assessed at $175,000. 

If several of your neighbors have recently foreclosed and the homes were purchased at auction, its going to drop the value of your home. While that may feel like a negative at the time, it should allow for a successful appeal for lowered property taxes.

Here is what the Clark County(Las Vegas, NV) Assessors Officer says if you feel you have a valid appeal: