A full season of youth hockey in the Twin Cities — association fees, ice time, equipment, tournament travel — commonly runs between two and six thousand dollars per child. At the elite club level, it goes higher.

Minnesota produces more Division I and professional hockey players per capita than any American state, and the pipeline that produces them has become, by the account of many people inside it, increasingly sorted by household income.

The costs are not primarily greed. Ice is expensive: a sheet costs millions to build and hundreds of dollars per hour to rent, and refrigeration is a major utility expense. Equipment for a growing child must be replaced roughly annually.

What has changed is the calendar. Hockey was once a winter sport. Competitive youth hockey now runs most of the year, with spring leagues, summer camps and skills sessions that families describe as optional in theory and mandatory in practice.

"Nobody requires it," an association director in the northern suburbs said. "Every kid who makes the top team did it. Parents can read."

Associations have responded with scholarship funds, equipment exchanges and try-hockey-free events. The programs are real and reach hundreds of families annually. Directors are candid that they address entry rather than persistence.

The city's situation differs from the suburbs. Minneapolis has fewer sheets of ice per capita, and its public high school programs have struggled with participation numbers — several have cooperative agreements with neighboring schools to field a single team.

Meanwhile, girls' hockey has grown steadily, and Minnesota's programs remain among the strongest in the country. That growth has increased demand for ice without a corresponding increase in supply, which has pushed practice times for younger teams into hours that are hard on families.

Six a.m. practice for a nine-year-old is not a scheduling quirk. It is a rationing mechanism, and the families who can accommodate it are not randomly distributed.

Hockey Minnesota officials describe participation as roughly flat statewide, which is better than the national trend and worse than the demographic growth of the metropolitan area would predict.

The associations that have grown share a characteristic: they own or control their ice. The ones that rent are at the mercy of a market they cannot influence.