Critics of a suburban Denver school board that considered reviewing a U.S. history course to emphasize patriotism are turning in signatures to force a recall election for three conservative members responsible for the push.

A group of parents and educators called Jeffco United for Action plans to submit 30,000 recall signatures Tuesday to the county clerk's office. They need 15,000 valid signatures from Jefferson County voters for each board member they're trying to oust.

The group says it's seeking to recall three of the five board members because the conservative majority last year considered reviewing the new Advanced Placement U.S. history curriculum. That prompted waves of student protests in the suburban Denver district.

The group also is critical of the board for paying $280,000 to the superintendent it hired.