Born in Madison, Wisconsin, Tarpley grew up in Kalamazoo, Michigan, and attended Portage Central High School from 1998 to 2002.

During her sophomore season, Tarpley led the nation in total points (goals and assists) while leading the Tar Heels to the 2003 NCAA Women's Soccer Championship.

Her number 25 jersey was retired by the school in February 2006 during the halftime of a North Carolina Tar Heels men's basketball game.

She was allocated to Chicago Red Stars along with USWNT players Carli Lloyd and Kate Markgraf.

In the inaugural 2009 Women's Professional Soccer season, Tarpley appeared in 17 games (16 starts, 1321 total minutes) and scored four goals and four assists.

With the Athletica, she joined former North Carolina Tar Heel standouts Lori Chalupny, Kendall Fletcher and Kristina Larsen.

Following her ACL injury in 2011, Tarpley was selected by the Chicago Red Stars in the 2013 NWSL Supplemental Draft but waived by the team in March 2014.

She earned her 100th cap on July 16, 2008, against Brazil in the last game before the 2008 Olympics, the 23rd player in USWNT history to reach this feat.

[6] A torn anterior cruciate ligament sustained in a warm-up match with Japan saw Tarpley ruled out of the 2011 FIFA Women's World Cup.