Lake Sammamish (Lushootseed: sc̓ababš) is a freshwater lake located 8 miles (13 km) east of Seattle in King County, Washington, United States. The lake is 7 miles (11 km) long and 1.5 miles (2 km) wide. Its maximum depth is 105 feet (32 m), and its surface area is 8 square miles (21 km²). It is situated east of Lake Washington and west of the Sammamish Plateau. The lake extends from Issaquah in the south to Redmond in the north. At Issaquah, the lake is fed by Issaquah Creek, and at Redmond, it drains into Lake Washington through the Sammamish River, which is named after the native people who once lived along its entire length. The Sammamish People refer to the lake as sc̓ababš, which means "little lake" in their language.

The Lake Sammamish watershed covers 98 square miles (250 km²) and spans from Redmond through Bellevue and Issaquah to Preston and Hobart. It includes many creeks that flow into the lake. Issaquah Creek is the largest tributary and provides more than 70% of the water that flows into the lake.

Development

The area around Lake Sammamish has been growing quickly in recent years. It is the fastest-growing suburban area in the Greater Seattle Metropolitan Area. Between the late 1990s and early 2000s, cities like Redmond, Snoqualmie, Fall City, Issaquah, and Bellevue experienced significant growth. The city of Sammamish was incorporated in 1999 due to the growth in the suburbs.

Ecology and conservation

In the past, heavy rain in the area around Lake Sammamish, which gets nearly twice as much rain each year as Seattle, was absorbed by the forests nearby. These forests had soft, sponge-like soil that helped reduce runoff during winter storms and refilled underground water sources. These water sources then released fresh water to streams during dry summer months. However, as cities grew quickly, many forests were replaced by surfaces that do not allow water to pass through, such as rooftops, roads, and parking lots. This change caused more stormwater to flow into streams and the lake, carrying dirt and harmful chemicals. This made the water less clear and hurt fish and wildlife.

In May 2010, the federal government asked the city of Sammamish to stop building homes and other structures within 250 feet (76 meters) of the lake’s edge to protect salmon and steelhead fish. The report did not mention Lake Sammamish kokanee salmon as a species in danger, even though scientists and environmental groups warned that development along the shore and changes to nearby streams had nearly driven the kokanee salmon to local extinction. While Sammamish did not follow the recommendation, the city of Issaquah already limits development within 200 feet (61 meters) of the lake, Issaquah Creek, and the East Fork of Issaquah Creek through its Shoreline Management Program. Experts estimate that fewer than 100 kokanee salmon remain in Lake Sammamish.

The recent return of beavers to Lake Sammamish has caused concern for officials in the City of Issaquah and Lake Sammamish State Park. These officials believe the beavers may cause flooding and dig tunnels under roads. They are suggesting that the beavers be moved to another area. On July 6, 2010, officials from the City of Issaquah asked the Washington Department of Fish and Wildlife to remove a beaver dam on Tibbetts Creek in Lake Sammamish State Park because of worries about possible flooding and barriers for salmon.

In contrast, studies in northern areas of the United States and Canada show that beavers help ecosystems by creating ponds that increase the number and variety of fish and birds. Research in the Stillaguamish River basin, about 50 miles (80 kilometers) north of Lake Sammamish, found that when beaver ponds were lost, there was an 89% drop in the number of young coho salmon produced in summer and an 86% drop in the ability of winter habitats to support fish.

Recreation and parks

Lake Sammamish is next to Marymoor Park at the lake’s northern end, Lake Sammamish State Park at the southern end, and the East Lake Sammamish Trail. Lake Sammamish State Park has nine public boat launches. These launches are available through a separate entrance, for a fee, and include parking and restrooms.

The public can reach the lake’s western shore at Redmond’s Idylwood Park. The privately owned Vasa Park Resort in Bellevue also provides access from the west for a fee. Vasa Park offers one ramp for launching watercraft. Some housing developments have small, private parks that give their residents access to the lake.

Popular activities on the lake include rowing, fishing, waterskiing, wakeboarding, wakesurfing, tubing, and jet skiing. A public slalom course for waterskiing is located at the far northern end of the lake, stretching from the west to the east. In the mid-1980s, a local radio personality named Pat O’Day suggested moving the Seafair Cup hydroplane races from Lake Washington to Lake Sammamish. This proposal was not successful.

Lake Sammamish has many fish species available for fishing, including perch, smallmouth bass, largemouth bass, cutthroat trout, salmon, and steelhead trout, among others.

Events

• On July 14, 1974, serial killer Ted Bundy took two women from a beach at Lake Sammamish State Park during the day by pretending to be hurt and asking for their help.
• In 1991, Randy Roth killed his fourth wife, Cynthia, by drowning her in Lake Sammamish after leaving the Idylwood Park in Redmond using a raft.