Schrock was appointed to the legislature on Dec. 31, 1990 to represent the 39th Nebraska legislative district to replace William E. Barrett who was elected to Congress. He left office in 1993 because of redistricting and was then elected to the in 1994 to represent the 38th Nebraska legislative district. He was reelected in 1998 and 2002. He sat on the Education committee, the Committee on Committees and was the chairperson of the Natural Resources committee. Because Nebraska voters passed Initiative Measure 415 in 2001 limiting state senators to two terms after 2001, he was unable to run for reelection.