Raw steel production in the country's Great Lakes region was 610,000 tons in the week that ended Saturday, according to estimates from the American Iron and Steel Institute.
Production was up 25,000 tons from the week prior. Raw steel from Indiana and the Chicago area typically represents the majority of production in the Great Lakes region.
Production in the Southern District was estimated at 666,000 tons during the period that ended Sept. 15, down from about 674,000 tons a week earlier.
Domestic mills produced more than 1.8 million tons of steel last week, down 2.3 percent from the same period in 2011.
U.S. steel mills operated 73.5 percent of the available production capacity last week, which is up from a 73.3 percent production rate a week earlier.
An estimated 70.6 million tons of steel has been produced so far in 2012 at domestic steel mills, compared to about 67.4 million tons made through the same time frame last year.