WASHINGTON—Interior Secretary Ken Salazar says thousands of Interior Department workers would be furloughed, and thousands more seasonal workers would not be hired under automatic spending cuts set to take effect Friday.

Visiting hours at all 398 national parks are likely to be cut and sensitive areas would be blocked off to the public under what Salazar termed "draconian" cuts required by a budget-cutting law. Salazar said the park service's $112 million in cuts are especially grim, since they hit as parks are preparing for an influx of spring and summer visitors.

Salazar and National Park Service director Jon Jarvis said visitors will encounter fewer rangers, locked restrooms and see trashcans emptied less often if Congress does not reach a deal to avoid 5 percent across-the-board cuts.