Stephens Passage is an important waterway in the Inside Passage, running between the mainland and Admiralty Island. About 100 miles long, Juneau is near the north end of the waterway and Petersburg is near the south end.
The southern end of Stephens Passage is a hot spot for humpback whales. Whales are common in these waters from May through September, and in late summer, the greatest concentrations of feeding humpbacks in Southeast Alaska may be found in Stephens Passage. Groups containing as many as 30 whales have been seen feeding in these waters.
A small group of islands known as The Brothers sits at the southeast corner of Admiralty, at the junction of Frederick Sound and Stephens Passage. Sea Lion Island, one of The Brothers, is home to one of the largest year-round colonies of Steller sea lions in Southeast Alaska. Researchers have been monitoring and observing these animals in recent years.
Biologists on The Brothers report harlequin ducks, red-breasted mergansers, Pacific loons, surfbirds and black turnstones in the nearshore waters, as well as black oystercatchers - a striking black shorebird with a bright red bill and feet. River otters and kingfishers ply the shoreline. Harbor seals are abundant, and transient killer whales hunt seals and sea lions in the area.
About halfway between Petersburg and Juneau two picturesque glacial fjords, Tracy Arm and Endicott Arm, flow into Holkham Bay. The scenery, fishing and wildlife viewing make this area - a designated wilderness - a popular destination. Sumdum Glacier overlooks Holkham Bay and can be seen on the southwest flank of Mount Sumdum, a prominent 6,666-foot peak that rises between the two fjords. Several tidewater glaciers calve icebergs into these arms, and these bergs often make it out into Stephens Passage before melting. In late spring and summer the protected, ice-choked waters of the upper arms shelter pupping harbor seals.
The coastline of Glass Peninsula, on the eastern shore of Admiralty Island, is prime bald eagle habitat. Biologists have found about one eagle nest per mile of coast here.
North of Tracy Arm, a prominent, clearcut swath runs along the mainland shoreline and parallels the coastline. This continues for about 45 miles from Port Snettisham to Juneau. High voltage power lines follow this corridor and deliver electricity to Juneau from a hydroelectric facility in Snettisham. As with other Alaska communities, the state capital is not connected to power grids in Canada or the Lower 48 states and must generate its own electricity.
Look for a small, dark-colored sea bird in the waters of northern Stephens Passage. Stephens Passage has the world's greatest concentrations of marbled murrelets. Pigeon guillemots, the marbled murrelets' larger cousins, can also be found here.
If you notice birds flying in long lines or rafted together in large groups on the water, these are likely sea ducks such as surf scoters and white-winged scoters. Relatively unremarkable at a distance, a look with binoculars reveals the striking orange and white facial markings of the males.
Cormorants may also be seen on the water or in flight. These are dark birds with a long neck and a hooked bill. Like long-tailed ducks, murres and loons, they are excellent swimmers. Cormorants have been documented diving as deep as 200 feet.
At the southern tip of Douglas Island is a broad expanse of open water where Stephens Passage, Gastineau Channel and Taku Inlet meet. There is a sea lion haulout on the mainland south of Taku Inlet and north of Grand Island, and sea lions are common in this area. See the Gastineau Channel chapter for more information on Taku Inlet.
The northern end of Stephens Passage runs between Douglas Island and Admiralty Island. In summer, the lush green alpine meadows above the treeline are home to Sitka black-tailed deer, and a sharp-eyed wildlife watcher with binoculars can pick out their reddish brown coats in the early morning or evening. Deer and black bears may also be seen on the beaches of Douglas Island. From late July through early September, runs of pink and chum salmon in area streams draw bears to the streamside.
The area north and west of Douglas Island is consistently good for seeing humpback whales. May and June are peak months here, but whales have been seen here every month of the year. Killer whales are also seen in these waters, sometimes in large pods of as many as 25 animals.