CHEYENNE - Fueled by healthy natural gas prices, the state's assessed valuation hit a historical high of $13.6 billion this year, a 32 percent jump over 2003, Wyoming Department of Revenue officials said Thursday.

Every county in the state saw its tax base increase, another measure of the state's relative prosperity during a period of high energy prices.

Local mill levies are applied to the assessed valuation in determining local property taxes.

"Even though it helps the mineral counties the most, it helps everybody," said Joe Evans, director of the Wyoming County Commissioners Association.

But an increase in the valuation of a county doesn't necessarily mean property owners will enjoy a tax break, Evans said.

"A lot of property taxes are set in stone by the Legislature, all the school mill levies and that kind of thing, and that's not something they're going to get a reduction in," he said.

A few counties, including Campbell County, have cut their mill levies, however, he said.

The state's natural gas valuation totaled $5.2 billion in 2004 from 273 producers. Last year the tally was $2.5 billion from 296 natural gas producers.

Second top-valued mineral was coal at $1.8 billion from 19 companies, compared with $1.7 billion last year from 18 producers.

Oil, once Wyoming's mineral king, was third at $1.2 billion from 538 producers. In 2003 oil was valued at $1 billion from 545 producers.

The valuation for all minerals increased by 53 percent.

"The big growth is in minerals," said Ken Ulrich, appraisal supervisor of non-mineral state property for the Department of Revenue.

He said non-mineral state assessed property, including utilities, increased about 5 percent in valuation.

Wyoming's last peak year was 2002, when the total assessed valuation was $10.3 billion. Before that, the historical high was $8.3 billion in 1985 during the state's last energy boom.

During the energy bust, the tax base dropped to a low of $5.7 billion.

Ulrich said Thursday the cyclical pattern is typical of the state's mineral rollercoaster. Evans said no one knows for sure how long this boom will last.

Campbell County remains the state's richest with a valuation of $3.2 billion, a 21 percent increase over 2003 and a new high. Of that total valuation, the local school mill levy on $2.686 billion will go to support Campbell County School District 1 public schools.

Second-wealthiest county is Sublette at $2 billion, a 118 percent jump over last year due almost solely to oil and gas production.

Next is Sweetwater County at $1.5 billion, up 34 percent.

At the other end of the scale, Niobrara County remained the state's poorest with a valuation of $43.7 million. But even Niobrara picked up $4 million in valuation.

All told, minerals' share of the total valuation increased from 54 percent to 63 percent, while residential property's share of the total declined from 22 percent to 18 percent.

Agricultural lands continue to represent a diminishing slice of the total state tax base, dropping from 1.51 percent to 1.32 percent.

Capital bureau reporter Joan Barron can be reached at (307) 632-1244 or at Joan.Barron@casperstartribune.net.