Salish Sea. The USGS definition of the San Juan archipelago coincides with San Juan County. Islands not in San Juan County are not part of the San Juan Islands, according to the USGS. At mean high tide, the archipelago comprises over 400 islands and rocks, 128 of which are named, and over of shoreline. The majority of the San Juan Islands are quite hilly, with some flat areas and valleys in between, often quite fertile. The tallest peak is Mount Constitution, on Orcas Island, at an elevation of . The coastlines are a mix of sandy and rocky beaches, shallow inlets and deep harbors, placid coves and reef-studded bays. Gnarled, ochre-colored madrona trees (Arbutus) grace much of the shorelines, while evergreen fir and pine forests cover large inland areas. The San Juan Islands get substantially less rainfall than Seattle, about to the south, due to their location in the rain shadow of the Olympic Mountains to the southwest. Summertime high temperatures are around , while average wintertime lows are in the high 30s and low 40s Fahrenheit (around 5 degrees Celsius). Snow is infrequent in winter, except for the higher elevations, but the islands are subject to high winds at times; those from the northeast sometimes bring brief periods of freezing. Present In the present, the San Juan Islands are an important tourist destination, with sea kayaking and orca whale-watching (by boat or air tours) being two of the primary attractions. San Juan Island's Lime Kiln Point State Park is a prime whale-watching site, with knowledgeable interpreters often on site. Politically, the San Juan Islands comprise by definition, San Juan County, Washington. Media based in and/or concerning the islands includes the Journal of the San Juan Islands and the Islands' Sounder. Transportation There are no bridges to the San Juan Islands; therefore, all travel from the mainland is either by water or by air. Water Four ferry systems serve some of the San Juan Islands. Washington State Ferries serves Lopez Island, Shaw Island, Orcas Island, and San Juan Island from terminals in Anacortes, Washington, and Sidney, British Columbia. Puget Sound Express provides passenger-only service from Port Townsend, on the northeast corner of the Olympic Peninsula, to Friday Harbor on San Juan Island. M/V San Juan Clipper of Clipper Navigation, Inc. provides high-speed water-jet–powered catamaran ferry service between San Juan Island and Seattle, Washington. Passenger-only ferries serve more islands. Passenger-only ferry