The calm waters of the Pacific Northwest are mostly off-limits to today's large cruise ships. As a result, these pristine waters, which are studded with islands, are an often-overlooked destination.

But for those who enjoy smaller, more intimate ships, the region offers a unique opportunity to explore an area abundant in natural wonders and rich in American history.Many islands in this region are inhabited only by bald eagles and deer. In fact, more bald eagles nest here than anywhere else in the United States.

Several small ships cruise areas such as the Gulf Islands and the inlets of British Columbia searching for whales, dolphins and other wildlife. Some sail the San Juan Islands, an archipelago of more than 170 forested islands, almost half of which are designated as national wildlife refuges protecting seals, sea lions, river otters and many species of pelagic birds.

From May through October, the Sea Bird and Sea Lion, two highly maneuverable 70-passenger ships operated by Special Expeditions, make seven-day departures from Portland, Ore., for "In the Wake of Lewis & Clark" voyages. Passengers travel inland from the mouth of the Columbia River to Idaho, more than 450 miles upstream. This route covers only a portion of the 1,200-mile journey of the united Columbia and Snake Rivers. More than 100 dams have been built along the rivers' tributaries (a watershed the size of France) and contain some of the highest canal lifts in the world. Fares start at $1,890. For more information, call (800) 762-0003.

The 49-passenger Executive Explorer also cruises the Lewis & Clark route, sailing 950 miles round trip through the locks and dams of the inland waterway system. The ship cruises Washington, Oregon and Idaho and offers an optional jet boat white-water excursion into the Snake River's Hell's Canyon. The Executive Explorer visits Fort Clatsop National Memorial (where the Lewis & Clark team wintered before embarking on their return journey), the "Turnaround" (the official end of the Lewis & Clark trail), and the twin cities of Lewiston, Idaho, and Clarkston, Wash., the Northwest's most inland seaports). Fares for six-day cruises start at $889 with departures from Portland through June 1. The cruises resume Sept. 5 through Nov. 29. For more information, call (800) 451-5952.

The Sea Bird and Sea Lion make six-day voyages from Seattle to Vancouver. With departures Sept. 10, 14 and 19, the boats cruise Puget Sound to Victoria, Princess Louisa Inlet and the San Juan Islands. These one-class ships feature all-outside cabins and landing crafts for inland exploring. Fares, which start at $1,350, include shore visits. For more information, call (800) 762-0003.

Clipper Cruise Line's 138-passenger Yorktown Clipper has an 11-day voyage that explores the Columbia River, Olympic Peninsula and British Columbia. The ship sails within touching distance of the Columbia River Gorge, Cascade Mountains and the San Juan and Gulf Islands. On-board lecturers discuss subjects ranging from the region's cultural and natural history to native Indian art and the logging industry. The Yorktown Clipper leaves May 18 from Portland with an itinerary that includes the Hood River, Columbia River Gorge, Astoria, Neah Bay, Port Angeles (for Olympic National Park, dominated by Mount Rainier), Matia Island Wildlife Refuge, Friday Harbor and a full day in Seattle. The reverse schedule is offered Oct. 1.For more information, call (800) 325-0010.