In 1900 the City Council bought the park from the estate of Mr. Phinney, in spite of vigorous protests over the price - $100,000 - and complaints that it was "too far out of town"! Another trolley line had been built to connect Seattle with the east and north side of Green Lake, and by 1904 it was extended on around the lake and through Woodland Park on a trestle.
In 1903/1910 the Olmsted Bros. included the development of Woodland Park in their comprehensive parks plan but the location of Aurora Avenue in 1932 voided their concept of Zoo expansion in that area. This was protested in vain and a beautiful forest area was removed - some trees were transplanted at Gilman and Wallingford Playgrounds. Dirt from the excavation was used to fill at the south end of Green Lake. The U. S. Army used "Lower Woodland" Park as a barracks site from 1941-1944.
Today the park is home to the Woodland Park Zoo and the Rose Garden. The Zoo is recognized as one of the best Zoos in the world, and houses nearly 300 species of wildlife. Adjacent to the Woodland Park Zoo, the Rose Garden is one of only two dozen certified American Rose Test Gardens in the United States. At its picturesque best from May through August, the garden displays new rose hybrids before they become available to amateur rose enthusiasts. Admission to the Rose Garden is free.
Beginning in 1911, the level of the lake was lowered seven feet, which added 100 acres of dry land once it had been graded and filled. This process was completed by the early 1930s with the filling of the southern end of the lake using material excavated from Woodland Park during the construction of Aurora Avenue in 1932. By 1909, the amusement park at the northwest corner of the lake had long ceased to operate and had become known as the "Old Picnic Grounds." In 1914, the Parks Department constructed the first frame bathing station at the southwest corner of the lake where Guy Phinney had developed his Woodland Park. Within a year, it was necessary to enlarge the structure due to its popularity. However, its location proved to be problematic due to frequent water stagnation, which tended to attract waterfowl. As a temporary solution, the Parks Department moved the structure to the northern end of the lake in 1922. Five years later, the first phase of a new brick bathhouse was completed at the site of the "Old Picnic Grounds." Initially, only the north and sound ends containing the dressing room and restroom facilities for men and women were constructed. The following year, the central portion was completed, which contained a public lobby and locker room. At the same time, the Parks Department constructed identical bathhouses at Madrona and Seward Parks. However, the central portion of the Seward Park Bathhouse was not completed until 1940. It may have been at this time that the small concession stand was constructed just to the north of the bathhouse to serve swimmers who frequented the West Green Lake Beach. A 1930 photograph in the municipal archives appears to show this building on the western shores of Green Lake near the bathhouse. In subsequent years, additional concession facilities were constructed at the northeastern and southwestern corners of the lake. This building is significant for its association with the development of Green Lake Park.