Most of the Kalamazoo River in southern Michigan, contaminated by a 2010 oil spill, is open for recreational use, the EPA announced. City, state and federal agencies involved in cleanup operations in southern Michigan said 34 miles of the Kalamazoo were cleared for recreational use. Some of the waterways affected by a 2010 spill were reopened in April. \"The long wait to open most of the oil-damaged Kalamazoo River is now over -- just in time for summer,\" stated Susan Hedman, regional administrator for the Environmental Protection Agency. Line 6b of the Lakehead pipeline system ruptured in July 2010. Enbridge, the Canadian operator of the pipeline, estimates about 20,000 barrels of oil spilled into the Kalamazoo River and nearby waterways. The EPA warned that area residents may still see sheen in parts of the river. Some could be associated with residual oil, some may be natural or tied to recreational vehicles. The river was closed in July 2010 after the spill was reported near Marshall, Mich. Enbridge is working to replace parts of the line and cleanup operations continue. \"EPA will remain in the Marshall area until the cleanup is completed,\" said Hedman. The cause of the incident is under investigation.