With two large protests still unresolved for this year’s tax valuations, the time has come for Warren County supervisors to start reviewing lists prepared by the tax assessor’s office for next year.

The pending protests are from two of five local casino companies, Ameristar and Riverwalk. Both claim values set in 2009 for property taxes due in January were far too high. Casino representatives and Tax Assessor Richard Holland both said they followed state-set criteria, but came up with vastly different valuations. The cases are in court.

Ameristar’s claim centers on a structure connecting the parking garage to the main casino and on its cofferdam. The casino — long the market leader among Vicksburg’s gaming venues —argues it would pay more than $1.6 million in taxes on those two parcels, an amount the company claims is $437,842 higher than its own figures.

The company owns 20 parcels in Vicksburg, including the main casino, a gas station and an RV park. Land roll receipts show Ameristar paid taxes in full on its other 18 parcels, totaling $227,854.15.

Values on Riverwalk’s three parcels south of the Mississippi River bridges were set by Holland at $78,172,733. That company’s internal calculations showed the valuation should have been $30,735,385, according to its complaint. Riverwalk has paid $774,378.80, with $265,644.52 outstanding, including penalties, records showed.

No new numbers have emerged from meetings with attorneys for both casinos in the past month, Holland said. Riverwalk’s attorney, James L. Martin said more discussions were planned with the assessor. Elizabeth Hicks, counsel for Ameristar, declined comment.

Valuations set by Holland’s office are used to collect revenue for the county, the City of Vicksburg and the Vicksburg Warren School District. All three depend heavily on property tax revenue, especially school and county operations, which do not share in sales tax collections as the City of Vicksburg does.

Land rolls for 2010-11 are expected to be ready Tuesday for supervisors to peruse. By state law, rolls are to be equalized for consistency between assessments and value, usually a weeklong process. From there, the public has 30 days to view their property status and file written challenges if they object.

Holland said last week he doesn’t expect values to grow more than 1 percent because of slower commercial development. Three hotels, a major grocery outlet and completion of Riverwalk increased land values for 2009-10 by 5.9 percent, to $3,343,404,905.

New values are assigned to one-fourth of the county’s parcels each year, with this year’s reflecting reassessments of the county’s northern half. Higher land values last year increased tax bills for some despite supervisors keeping property tax rates steady. Current millage rates are 40.53 in the county, 46.2 for schools and 35.88 inside the city to make the total 122.61 mills and were unchanged from 2009.

Local government and school operations are also boosted by revenue-based taxes collected from casinos.