Changes are coming to the Western Conference next school year.

The Washington State Activities Association conducts enrollment counts every two years, and those tallies affect league alignments.

Stanwood and Marysville-Pilchuck drop from 4A to 3A and Lynnwood jumps to 4A in 2011-12.

Mount Vernon, currently a 3A school in the Northwest Conference, moves to 4A and will rejoin Wesco. (There are no other 4A schools in the Northwest Conference.) Mount Vernon has toggled between the two leagues the past 15 years as its enrollment fluctuated.

The shift results in 11 4A and 10 3A schools, and the Western Conference will divide each classification into two divisions:

Wesco 3A North: Oak Harbor, Everett, Marysville Getchell, Marysville-Pilchuck and Stanwood.

Wesco 3A South: Glacier Peak, Meadowdale, Shorecrest, Shorewood and Mountlake Terrace.

Wesco 4A North: Arlington, Lake Stevens, Monroe, Mount Vernon and Snohomish.

Wesco 4A South: Cascade, Edmonds-Woodway, Jackson, Kamiak, Lynnwood and Mariner.

With each new enrollment count, the WIAA places the largest 17 percent of the schools in 4A. The next 17 percent is 3A, and so forth. The enrollment figures are not official until the WIAA approves them next month.

The cut-off point between 4A and 3A will be about 1,300 students. Oak Harbor is the ninth largest of 64 3A schools (1,277), but only the fifth largest 3A school in Wesco.

Following are unofficial enrollment figures for the Western Conference schools:

4A: Kamiak, 1,845; Lake Stevens, 1,760; Mariner, 1,731; Jackson, 1,516; Cascade, 1,487; Monroe, 1,476; Mount Vernon, 1,446; Edmonds-Woodway, 1,397; Lynnwood, 1,396; Arlington, 1,348; and Snohomish, 1,332.

3A: Meadowdale, 1,301; Stanwood, 1,292; Glacier Peak, 1,280; Marysville-Pilchuck, 1,278; Oak Harbor, 1,277; Marysville Getchell, 1,260; Shorewood, 1,166; Everett, 1,137; Mountlake Terrace, 1,104; Shorecrest, 1,096.