Mercer Island is a city in King County, Washington, United States. It is located on an island of the same name in the southern part of Lake Washington. Mercer Island is part of the Seattle metropolitan area. The city of Seattle is to its west, and Bellevue is to its east.

The island is connected to the mainland by bridges that carry Interstate 90. These bridges link Mercer Island to Seattle in the west and Bellevue in the east. The Lacey V. Murrow Memorial Bridge and the Homer M. Hadley Memorial Bridge are special floating bridges across Lake Washington. They carry Interstate 90 and connect Mercer Island to Seattle. Another bridge, the East Channel Bridge, connects Mercer Island to Bellevue. Because it is closer to Bellevue, Mercer Island is often seen as part of King County's Eastside.

In 2020, the population of Mercer Island was 25,748 people. Mercer Island has one of the highest average incomes per person in Washington state. It is also known as one of the richest ZIP codes in the entire United States.

History of Mercer Island
- Connecting the Island with Bridges
- Mercer Island Becomes a City
Geography and Climate
- Mercer Island's Climate
Education on Mercer Island
Population and People
- Mercer Island in 2020
Culture and Events
- Sister City
- Annual Events
Notable People from Mercer Island
Transportation
Images for kids
See also

History of Mercer Island

The western side of Mercer Island was once home to two villages of the Snoqualmie people. These were Native American groups who lived there before settlers from Europe arrived. The island is named after the Mercer family from Seattle. Non-Native American people first settled on the island between 1870 and 1880. The Mercer brothers, Thomas Mercer and Asa Mercer, would often row from Seattle to the island to pick berries, hunt, and fish.

The first large settlement was called East Seattle. It was located on the northwest side of the island. In 1889, a man named C.C. Calkins built a big, fancy hotel called the Calkins Hotel. People would travel to the hotel by steamboat from places like Madison Park and Leschi Park. Important guests, including President Benjamin Harrison, stayed at the hotel. Sadly, a mysterious fire destroyed the hotel in 1908.

Even after the hotel burned down, Calkins Landing continued to be used. This helped more people settle on the island permanently. A busier town center with shops and businesses grew in the middle of the northern part of the island. This area now makes up most of the island's main residential and business areas.

Connecting the Island with Bridges

In 1923, the East Channel Bridge was built. This bridge connected Mercer Island with Bellevue. Later, in 1930, George W. Lightfoot asked for a bridge to connect Mercer Island to Seattle. The Lacey V. Murrow Memorial Bridge was built and opened in 1940. It is currently the second-longest floating bridge in the world. A second floating bridge, the Homer M. Hadley Memorial Bridge, was built next to it in 1989. These bridges carry Interstate 90, linking Seattle, Mercer Island, and Bellevue.

Mercer Island Becomes a City

The City of Mercer Island was officially formed on July 5, 1960. It included almost all of the island, except for a small business area. Just over a month later, on August 9, that small business area also became its own town, called the Town of Mercer Island. However, these two separate parts of the island joined together to become one city, the City of Mercer Island, on May 19, 1970.

Geography and Climate

Aerial view of the Interstate 90 floating bridge connecting Seattle and the northern part of Mercer Island

Mercer Island City Hall was located at 47°34′14″N 122°13′19″W / 47.57056°N 122.22194°W / 47.57056; -122.22194. However, it closed in April 2023 because asbestos was found in the building's air system. As of August 2024, the city is still planning for a new building.

The highest point on Mercer Island is about 335 feet (102 meters) above sea level. This peak is located near the center of the island.

Mercer Island covers a total area of about 12.90 square miles (33.41 square kilometers). About 6.38 square miles (16.53 square kilometers) is land, and 6.52 square miles (16.88 square kilometers) is water. The ZIP Code for Mercer Island is 98040.

Mercer Island is the most populated island located in a lake in the United States.

Mercer Island's Climate

Mercer Island has warm, but not too hot, and dry summers. The average monthly temperatures do not go above 71.6°F (22°C). This type of weather is called a warm-summer Mediterranean climate.

Education on Mercer Island

The Mercer Island School District runs seven schools on the island.

Four elementary schools: Lakeridge, Island Park, West Mercer, and Northwood.
One middle school: Islander Middle School.
One high school: Mercer Island High School.
One alternative secondary school: Crest Learning Center.

Mercer Island is also home to several private schools. These include St. Monica Catholic School, the French American School of Puget Sound, and the Northwest Yeshiva High School.

Population and People

Historical population
Census	Pop.	%±
1970	19,047	—
1980	21,522	13.0%
1990	20,816	−3.3%
2000	22,036	5.9%
2010	22,699	3.0%
2020	25,748	13.4%
2023 (est.)	24,742	9.0%
U.S. Decennial Census 2020 Census

About 25% of the homes in Mercer Island are Jewish. The island also has two synagogues (Jewish places of worship) and a Jewish Community Center.

Mercer Island in 2020

In 2020, there were 25,748 people living in Mercer Island. The city had 9,927 households and 7,105 families. The population density was about 4,034 people per square mile (1,558 people per square kilometer).

The racial makeup of the city was:

About 63.6% White
About 22.9% Asian
About 1.1% Black or African American
About 0.1% Native American
About 0.1% Pacific Islander
About 0.7% from other races
About 6.9% from two or more races.
About 4.6% of the population was Hispanic or Latino (of any race).

About 23.1% of the residents were under 18 years old. About 20.4% were 65 years or older. The average income for a household in Mercer Island was $150,506.

Culture and Events

Sister City

Mercer Island has a special connection with a city in another country. Its sister city is Thonon-les-Bains, which is in France.

Annual Events

Summer Celebration: This is a yearly festival that happens on the weekend after the 4th of July. It ran for 30 years before being stopped in 2019 due to budget reasons. However, it was brought back in 2022.
Mercer Island Farmers Market: This market takes place most Sundays from June to October. You can find local fruits, vegetables, and some crafts there. A special version of the market, called the Harvest Market, happens on a Sunday in November.

Notable People from Mercer Island

Many well-known people have lived in Mercer Island. Here are a few:

Paul Allen: He was a co-founder of Microsoft.
Matthew Boyd: A professional baseball pitcher for the Seattle Mariners.
Ann Dunham: She was the mother of former President Barack Obama.
Aaron Levie: The CEO and co-founder of Box, Inc..
Rashard Lewis: A former NBA basketball player.
Joel McHale: A famous actor and comedian.
Steve Miller: A musician from the Steve Miller Band.
Jordan Morris: A forward for the Seattle Sounders FC soccer team.
Alan Mulally: The former CEO of Ford.
Bill Russell: A legendary former NBA player and coach, who is in the Basketball Hall of Fame. He passed away on Mercer Island.
Kyle Seager: A former baseball player.
Quin Snyder: The head coach of the Atlanta Hawks basketball team.
Mary Wayte: A swimmer who won two Olympic gold medals.

Transportation

Mercer Island is divided by Interstate 90. This major highway connects the city to Seattle in the west and Bellevue in the east. The highway crosses Lake Washington on the Lacey V. Murrow and Homer M. Hadley floating bridges to Seattle. It then crosses the East Channel Bridge towards Bellevue. These bridges also have a path for walking and biking called the Mountains to Sound Greenway. A large part of the highway on Mercer Island is built below street level and covered by parks, known as the Mercer Island Lid.

Public transportation in Mercer Island is provided by King County Metro and Sound Transit. This mainly includes express bus routes that go to Seattle and the Eastside. Many routes connect to a park and ride facility on the north side of the island, where people can park their cars and take a bus. This facility was expanded in 2008.

In early 2025, a light rail station will open at the park and ride. This will be part of the 2 Line and will offer train service to Seattle and the Eastside. The light rail will replace some of the express bus routes on Interstate 90. Mercer Island is expected to become a major place where people switch between buses and trains.

Images for kids

Aerial view of Mercer Island from the north
Seal of Mercer Island
Location of Mercer Island in King County, Washington

Mercer Island, Washington facts for kids

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