2011 || Sophomore
Came off the bench to record a kill against No. 15 Colorado State in the season opener...tallied a season-high three kills on three swings againt Charleston Southern at the Deacon Invitational...season-high two digs at No. 18 Oklahoma...recorded first kill and block of the SEC season at Georgia...had two kills at No. 16 Kentucky, her most during the conference season.

2010 || Freshman
Koop saw action in 28 of Arkansas' 31 matches with 13 starts. She finished the season averaging 1.36 kills per set and had 10 matches with at least six kills. In the team's first road match of the year, Koop came off the bench to pound a career-high 12 kills in a five-set win at Oral Roberts. She hit .364 and added three digs in the match. At the Middle Tennessee Invitational, Koop totaled 21 kills and 11 digs, including nine kills and four digs in the Razorbacks' finale against Alabama-Birmingham. In back-to-back SEC matches, she had nine and 10 digs in road wins at Alabama (Sept. 26) and South Carolina (Oct. 1), respectively. She later equaled the season-best 10 digs in Arkansas' four-set match against No. 1 Florida (Nov. 19). Koop also had season-best efforts of five total blocks at Mississippi State (Sept. 24) and a .500 hitting percentage-on 10 kills-also against Mississippi State (Oct. 31). In her final match of the season, she had four kills, two service aces, five digs and four total blocks against South Carolina (Nov. 21). Koop was named to Arkansas' Athletic Department Honor Roll for her work in the classroom during the 2010 fall semester.

Prior to Arkansas
Koop was named to the American Volleyball Coaches Association (AVCA) 2009-10 Under Armour Girls High School All-America Watch List. She was selected to the 2010 Texas Girls Coaches Association 5A All-State Team and was one of 12 players in the state named to the 4A-5A East All-Star Team. Playing for Klein High School, Koop led the Houston area with 5.20 kills per game and was fourth with 4.43 digs per game. She was also a member of the Lonestar Volleyball All-Texas team and was named a PrepVolleyball.com Senior Ace. A starter for Klein High School since her sophomore season, Koop was twice named the 2007 and 2009 Most Valuable Hitter of her district and earned district MVP as a junior. She also earned first-team all-district honors twice. Koop has been a member of the Texas Tornados top team since the 12's level. Her club team won two bronze medals in the National division of the 2006 and 2007 Junior Olympics. Koop helped lead the Texas Tornados to a 17th-place and fifth-place finish in the Open division of the Junior Olympics as a sophomore and junior, respectively.

Personal
Born Nov. 7, 1991, Hayley Louis Koop is the younger of two children to Brian and Becky Koop of Spring, Texas. She has an older sister, Katelin, who was setter at East Carolina (2007-09). Koop will be an art major at Arkansas.