Question: In what part of California is the headquarters of Winzler & Kelly?

full_context: Document 1: Seattle: Prior to moving its headquarters to Chicago, aerospace manufacturer Boeing (#30) was the largest company based in Seattle. Its largest division is still headquartered in nearby Renton, and the company has large aircraft manufacturing plants in Everett and Renton, so it remains the largest private employer in the Seattle metropolitan area. Former Seattle Mayor Greg Nickels announced a desire to spark a new economic boom driven by the biotechnology industry in 2006. Major redevelopment of the South Lake Union neighborhood is underway, in an effort to attract new and established biotech companies to the city, joining biotech companies Corixa (acquired by GlaxoSmithKline), Immunex (now part of Amgen), Trubion, and ZymoGenetics. Vulcan Inc., the holding company of billionaire Paul Allen, is behind most of the development projects in the region. While some see the new development as an economic boon, others have criticized Nickels and the Seattle City Council for pandering to Allen's interests at taxpayers' expense. Also in 2006, Expansion Magazine ranked Seattle among the top 10 metropolitan areas in the nation for climates favorable to business expansion. In 2005, Forbes ranked Seattle as the most expensive American city for buying a house based on the local income levels. In 2013, however, the magazine ranked Seattle No. 9 on its list of the Best Places for Business and Careers.
Document 2: Rosenberg's Department Store: Rosenberg's Department Store is located at Fourth and D Streets in downtown Santa Rosa, California. The structure is the most significant example of the Streamline Moderne style in Santa Rosa, and was the tallest building in the city for many years.
Document 3: Susan Winchester: Susan Winchester, born in Chickasha, Oklahoma, earned her bachelor's and master's degrees at the University of Oklahoma. Winchester co-owned and operated American Dusting Company and Chickasha Flying Service from 1976 to 1989, after which she worked as a coordinator for Adult Training and Development at Canadian Valley Technology Center. In 1992 she started Winchester Group, an educational group that provides training and consulting to businesses.
Document 4: San Diego: San Diego hosts several major producers of wireless cellular technology. Qualcomm was founded and is headquartered in San Diego, and is one of the largest private-sector employers in San Diego. Other wireless industry manufacturers headquartered here include Nokia, LG Electronics, Kyocera International., Cricket Communications and Novatel Wireless. The largest software company in San Diego is security software company Websense Inc. San Diego also has the U.S. headquarters for the Slovakian security company ESET. San Diego has been designated as an iHub Innovation Center for collaboration potentially between wireless and life sciences.
Document 5: Naval Auxiliary Landing Field Santa Rosa: Naval Auxiliary Landing Field (NALF) Santa Rosa, California, also known as Naval Auxiliary Air Station, Santa Rosa, was a military airport located in Santa Rosa, California, in Sonoma County, California, USA.
Document 6: Clean Water Services: Clean Water Services is the water resources management utility for more than 600,000 residents in urban Washington County, Oregon and small portions of Multnomah County, Oregon and Clackamas County, Oregon, in the United States. Clean Water Services operates four wastewater treatment facilities, constructs and maintains flood management and water quality projects, and manages flow into the Tualatin River to improve water quality and protect fish habitat. They are headquartered in Hillsboro.
Document 7: Winzler & Kelly: Winzler & Kelly was an engineering and environmental services firm based in Santa Rosa, CA, with offices in California, Oregon, Washington, Guam, and Saipan. It was recognized as a "Best Multidiscipline A/E Services Firm to Work For" by "CE News" in 2010.
Document 8: Santa Rosa Rugby Club: The Santa Rosa Rugby Club is a men's rugby union team based in and around Santa Rosa, California. The club was founded in 1971. The team plays in the Northern California Rugby Football Union at the Division I level. The Santa Rosa Rugby Club won back to back national championships in 1994-95.
Document 9: Seattle: Still, very large companies dominate the business landscape. Four companies on the 2013 Fortune 500 list of the United States' largest companies, based on total revenue, are headquartered in Seattle: Internet retailer Amazon.com (#49), coffee chain Starbucks (#208), department store Nordstrom (#227), and freight forwarder Expeditors International of Washington (#428). Other Fortune 500 companies popularly associated with Seattle are based in nearby Puget Sound cities. Warehouse club chain Costco (#22), the largest retail company in Washington, is based in Issaquah. Microsoft (#35) is located in Redmond. Weyerhaeuser, the forest products company (#363), is based in Federal Way. Finally, Bellevue is home to truck manufacturer Paccar (#168). Other major companies in the area include Nintendo of America in Redmond, T-Mobile US in Bellevue, Expedia Inc. in Bellevue and Providence Health & Services — the state's largest health care system and fifth largest employer — in Renton. The city has a reputation for heavy coffee consumption; coffee companies founded or based in Seattle include Starbucks, Seattle's Best Coffee, and Tully's. There are also many successful independent artisanal espresso roasters and cafés.
Document 10: John Skilling: John Skilling graduated from the University of Washington in 1947 and started working for an engineering firm called W.H. Witt Co, which is now known as Magnusson Klemencic Associates. He married at a young age and had three children—two girls and a boy.
Document 11: San Francisco: San Francisco (initials SF) (/ ˌsæn frənˈsɪskoʊ /, Spanish for Saint Francis; Spanish: (san franˈsisko)), officially the City and County of San Francisco, is the cultural, commercial, and financial center of Northern California. The consolidated city - county covers an area of about 47.9 square miles (124 km), mostly at the north end of the San Francisco Peninsula in the San Francisco Bay Area. It is the fourth-most populous city in California, and the 13th-most populous in the United States, with a 2016 census - estimated population of 870,887. The population is projected to reach 1 million by 2033. As of 2016, San Francisco County was the 7th highest - income county in the United States, with a per capita personal income of $110,418.
Document 12: Graton, California: Graton is an unincorporated town and census-designated place (CDP) in west Sonoma County, California, United States. The population was 1,707 at the 2010 census. Graton's ZIP code is 95444. The town also has a culinary reputation attributed to two restaurants in the area.
Document 13: Santa Rosa, California: Santa Rosa (lit. Spanish for ``Saint Rose '') is a city in and the county seat of Sonoma County, in California's Wine Country. Its estimated 2016 population was 175,155. Santa Rosa is the largest city in California's Redwood Empire, Wine Country and the North Bay; the fifth most populous city in the San Francisco Bay Area after San Jose, San Francisco, Oakland, and Fremont; and the 28th most populous city in California.
Document 14: Santa Rosa, California: Santa Rosa is a city in and the county seat of Sonoma County, California, United States. Its estimated 2014 population was 174,170. Santa Rosa is the largest city in California's Redwood Empire, Wine Country and the North Bay; the fifth most populous city in the San Francisco Bay Area after San Jose, San Francisco, Oakland, and Fremont; and the 28th most populous city in California.
Document 15: Santa Rosa Creek Reservoir: Santa Rosa Creek Reservoir is a reservoir in Spring Lake Regional Park in the city of Santa Rosa, California, USA. It is impounded by an earthen dam built in 1963 and owned by the Sonoma County Water Agency.
ground_truth: Sonoma County
sub_queries: Winzler & Kelly >> headquarters location Answer: Santa Rosa
what part of california is Santa Rosa in Answer: Sonoma County