GRAND RAPIDS, Minn. (AP) _ A crude-oil spill on March 3 was 1.7 million gallons, nearly three times bigger than previously estimated, the company that owns the ruptured pipeline said.

The new estimate released Tuesday makes it the state's largest recorded pipeline spill. The same 34-inch pipeline outside this northern Minnesota city was responsible for the second worst spill of 1.3 million gallons in 1973 near Argyle.

About 340,000 gallons from the latest spill flowed into the Prairie River through a storm sewer, Lakehead Pipe Line Co. said.

The company previously estimated about 630,000 gallons of oil spilled. Workers have collected 2 million gallons of oil and oil-contaminated water from the leak site, the company said.

State officials have said there are no indications the oil has reached the Mississippi River, but Minnesota Health Department officials plan to monitor the St. Cloud municipal water intake sites on the river.

Harm to fish and wildlife has been minimal, said Jean Bergerson, public information officer for the Minnesota Department of Natural Resources.

Including the March 3 spill, about 4 million gallons of oil have spilled from the pipeline in 16 incidents since the early 1970s, according to state records.

Ivan Huntoon, regional chief of the Federal Office of Pipeline Safety in Kansas City, said the cause of the latest rupture probably will take months to determine.