border is Beverly Avenue until 103rd Street (when it shifts to Vincennes Avenue). The area contains the neighborhoods of Brainerd, Washington Heights, and Fernwood, and covers an area of . It is geographically divided by the Metra Rock Island Line tracks and Interstate 57. Washington Heights, Morgan Park, Beverly, Mount Greenwood, and Blue Island are considered part of the Blue Island Ridge. The ridge is a glacial bluff which was named for its color, due to atmospheric conditions or its blue wildflowers. the area had of single-family housing, of multifamily housing, of commercial development, of industrial development, of institutional development, and of mixed-use development. An additional was defined as transportation and other. About three-quarters of the housing stock, 74.3 percent, in Washington Heights of single-family detached homes. Most of the houses (57.5 percent) were built between 1940 and 1969. The median number of rooms in an area house is 6.4, compared to 4.8 rooms citywide. 88.6 percent of the housing units were occupied , compared to a 90.1-percent occupancy rate . Of the total number of units, 67.7 percent were owner-occupied and 32.3 percent were renter-occupied , compared to 69.5 percent and 30.5 percent . Between 51 and 100 multifamily buildings in the area were considered affordable . Brainerd The original Brainerd settlement was bounded by 87th and 91st Streets and Racine and Ashland Avenues. The modern neighborhood is bounded by 89th Street, Princeton Park, 95th Street, and Beverly Boulevard. It contains the Brainerd Bungalow Historic District, which was added to the National Register of Historic Places in 2016. The historic district is roughly bounded by 89th Street, 95th Street, Loomis Street, and May Street. It consists of bungalows built between 1915 and 1931, with construction peaking in 1927. The district experienced a construction boom during the 1910s and 1920s, and its construction mirrors that of similar contemporary districts across the United States. Although 42 architects are known to have designed the district's buildings, several (including William E. Sammons, Braucher, McClellan, Joneke, and Johnson) dominated the construction. Almost half of the buildings have no known architect, however, and relied on preexisting building plans. In addition to the bungalows which make up most of the district's buildings, several multi-family residential buildings (duplexes and apartment buildings) are stylistically similar. Fernwood Fernwood is in southeastern Washington Heights. Established in 1883, it was annexed by Chicago in 1891. Parts of Fernwood extend into nearby