The league offers championships for girls in basketball, cross country, golf, softball, tennis, track & field, and volleyball.
In boys sports, the SEK offers championships in baseball, basketball, cross country, football, golf, soccer, tennis, track & field, and wrestling.
The original eight members were Chanute, Coffeyville, Columbus, Fort Scott, Independence, Iola, Parsons, and Pittsburg.
The conference was split into "Upper" and "Lower" divisions for football from 1981 to 2003 as the Kansas State High School Activities Association's district system made it no longer possible for every league team to play each other in football.
In 2004, the league went back to a single division format for football but each school was not required to play each of the other eight as this is still not possible due to district assignments.
Pittsburg began playing as a football independent in 2016 when the playoff systems changed for Class 6A and 5A schools.
Pittsburg cited a need to play larger schools in order to improve its seeding in the post-season.
Parsons administrators also expressed a desire to play competition closer to the school's level.
For all other sports, enrollment numbers from grades 9-12 are used to determine classes for the current school year.