William D. Slater, 83, of Youngsville, and formerly of Clarendon and Warren PA., passed away on Tuesday, December 14, 2010 at the Rouse Warren County Home. Mr. Slater was born October 10, 1927, in San Juan, Puerto Rico, the son of the late Walter R. and Cecile Lesser Slater. William was a Warren resident most of his life graduating from Warren High School in 1946 and the Carnegie School of Medical Technology in Cleveland, Ohio in 1950. He was employed as a Laboratory Supervisor for the Warren Medical Group Laboratory for thirty-eight years retiring in 1993. William was a veteran of World War II serving in the Army during the Occupation in Japan and Germany and serving again during the Korean War as an S/SGT. He was a member of the Grace United Methodist Church, Warren, a member, Past Master and Past Secretary of the Joseph Warren Lodge No. 726, F & AM, member of the Coudersport Consistory, member of the Board of Directors or Masonic Temple Association, member of the A. A. S. R. and was a past officer of the Council of the Princes Of Jerusalem of the Consistory. He received the 33rd Degree of the Scottish Rite of Freemasonry in Boston in 1996. He had been active in the old Warren County Hot Stove Boys Baseball League for many years and was an avid fly fisherman who also enjoyed tying his own flies. He also will be remembered for his wonderful flower and vegetables gardens. He is survived by, his wife, Barbara Haight Slater, whom he married August 29, 1987; two sons, David Slater and his wife Jody, Sugar Grove, and Mark Slater and his wife Vicky, Jefferson, MD; a daughter Linda Eby and her husband William, Woodinville, WA; two stepdaughters, Amy Knopf and her husband Kevin, Warren, and Bonnie Hoover and her husband Don, Phoenix, AZ; four grandchildren, Matthew Slater, Nicholas Eby, Kate Eby, and Victoria Brecht