Lake Hudson (Oklahoma)  Lake Hudson, also known as Markham Ferry Reservoir, is a man-made reservoir in Mayes County, Oklahoma, United States, about northwest of Locust Grove, Oklahoma and southeast of Pryor, Oklahoma. It was created by the completion of the Robert S. Kerr Dam on the Grand River in 1964. It is managed by the Grand River Dam Authority (GRDA). GRDA began construction of the Markham Ferry Dam in December 1961. This was the second of GRDA's hydroelectric projects along the Grand River. The first was Pensacola Dam, which created Grand Lake o' the Cherokees. The Markham Ferry project was completed in April 1964. The lake was named for Washington ("Wash") E. Hudson, an early-day Tulsa attorney, Oklahoma state legislator, and member of the Board of the Grand River Dam Authority (GRDA) from 1955 until he died in 1964. In 1923, he founded the Tulsa Law School. Researchers reported in 2018 that Wash Hudson was an incorporator of the Tulsa Benevolent Society in 1922, which established the Ku Klux Klan in Tulsa in the following year. A GRDA spokesman told the reporter that GRDA would investigate the feasibility of renaming the lake, in view of these reports. He had said that the utility had never before received any complaints about the lake name, nor about Mr. Hudson himself. GRDA spokesman John Wiscaver says the agency investigated Hudson's background after being approached by the online publication "The Frontier", which first reported the proposed name change. Wiscaver said it's "fairly clear" Hudson was involved with the KKK and the GRDA supports the bill. The lake would become Lake Markham in honor of a Cherokee family that operated a ferry service on a portion of Grand River that is now part of the lake. The Robert S. Kerr Dam structure is a concrete gravity and earth filled embankment with a concrete ogee weir spillway. The length is , including the powerhouse,and the height is about above the stream bed. The spillway has seventeen gates, each , operated by two traveling gate hoists. Its capacity is per second. The lake has a surface area of , a shoreline of , and a "normal" level (being the top of its conservation pool) of above sea level. The normal storage capacity is . The top of the flood control pool is at above sea level. Kerr dam has a crest elevation of above sea level. The powerhouse has four hydroelectric turbines, providing a total capacity of 114,000 kW.