WASHINGTON — Alaska's Tongass National Forest should not be exempt from the U.S. Department of Agriculture's "roadless rule," a federal district court ruled Thursday.

The ruling by the U.S. District Court for the District of Columbia marks the latest twist in a fight that has spanned 16 years in federal courts. Judges have flipped back and forth over whether the rule is valid and whether the federal government could exempt the Tongass from it.

The rule restricts road construction and timber harvesting in national forests. The Tongass is the nation's largest national forest, stretching 16.8 million acres across Southeast Alaska.

This week's decision hands a "no" to the state of Alaska and numerous other organizations, including the Alaska Forest Association, the Juneau Chamber of Commerce and the City of Ketchikan. They argued, this time, that the rule violated a slew of laws, including the National Environmental Policy Act, the Wilderness Act and the Administrative Procedure Act.

Alaska and its co-litigants argued that the USDA didn't consider the needs of individual states when it crafted the rule, particularly for multiple-use management on national forest lands.

The rule was issued in the last days of the Clinton administration, in 2001. Alaska sued then, and ultimately the George W. Bush administration said it would exempt the Tongass from the rule temporarily, and later on a permanent basis.

In 2011, a federal court tossed the Tongass exemption. Later, an appeals court reversed the decision. Then a full "en banc" panel of that appeals court reversed it again. The Tongass, ultimately, had to abide by the roadless rule.

On Thursday, the district court judge held that line, saying the rule stands and the USDA did not violate any laws in crafting it.

Cori Mills, an assistant attorney general for Alaska, said the state is disappointed with the ruling and is still reviewing its appeal options.