Washington is called the Evergreen State due to its physical geography and climate. Much of this state's terrain is made up of deep green forests of pine and fir trees. Large amounts of annual rainfall account for the state's richly green landscapes. This state nickname is also sometimes attributed to Washington's plentiful national parks and protected wildlife preserves. The prominence of deep green is apparent in some of Washington's other state symbols such as the color of its flag.
The origins of Washington's state nickname can be traced to the late 19th century when the state first became an official part of the United States. A real estate professional named Charles T. Conover suggested the moniker Evergreen State in 1890 as a tribute to the green landscapes that were visible from his home in Seattle. The Washington state legislature officially signed the nickname into law in 1893. Some residents occasionally refer to their state with the unofficial nickname of the Green Tree State, although this name is usually not as well known.
Frequent rainy weather is a notable contributing factor to Washington becoming nicknamed the Evergreen State. This state has one of the highest levels of annual precipitation in the United States (US), as an average year in Washington state sees around 160 inches (about 407 cm) of rain. Rainfall is often the most concentrated in certain western regions of the state such as the Olympic Peninsula. High levels of humidity also keep the Evergreen State's grass and other plants consistently green when the same types of vegetation normally dry out in other regions during warmer summer months. Summer in Washington is normally the only season with days of noticeable sunlight, and long-time residents often claim that long months full of gray clouds are a trade-off for the lush green land.
Washington has some of the most visually striking national parks such as Olympic National Park and the North Cascades National Park. These protected wilderness areas are known for their evergreen trees that can rival some multistory buildings in height. Some of these trees have also thrived in the rainy weather for hundreds of years.
The Evergreen State is the only state in the US to be named after one of the nation's presidents. Washington's state flag is made up of a solid green background with a seal depicting a portrait of George Washington. Many native state residents identify just as much with their state's signature green color as with Washington's namesake.