PORTLAND, Maine — A former Acadia National Park superintendent accepted an illegal gift of a Caribbean family vacation valued at more than $14,000 months before his retirement in 2015, according to a report released Thursday. The report was issued by the inspector general of the U.S. Department of the Interior, which oversees the management of federal lands and natural resources. A lawyer for Sheridan Steele, target of the probe, contends there was nothing illegal about the retirement gift announced at a dinner attended by dozens of members of the local community on Mount Desert Island. “We don’t deny the facts, but we deny the conclusion.