Deer Park is a city in Spokane County, Washington, United States. The population was 3,652 at the time of the 2010 census, up from 3,017 i…Deer Park is a city in Spokane County, Washington, United States. The population was 3,652 at the time of the 2010 census, up from 3,017 in 2000. North of Spokane, the city of Deer Park was officially incorporated 116 years ago on June 24, 1908. Deer Park got its name when railroad surveyors saw deer grazing in the area. It was settled in 1889 when a railroad siding was built for the Spokane Falls & Northern Railway. Soon the Standard Lumber Company sawmill was established by William Short and George Crawford to provide the lumber needed to rebuild the nearby city of Spokane Falls following the great fire of 1889. By 1900 the population of Deer Park was approximately 300 residents. In addition to the sawmill, the community consisted of three general stores, a blacksmith and harness shop, a livery and feed stable, Jeff Moore's hotel, Dr. Prince's drug store, a public school with approximately 75 students, and a Congregational church led by Rev. F. McConaughy. By this time there were as many as eight sawmills within ten miles of Deer Park, all of which got their supplies in, and employed residents of, the town.