A national memorial to military women is celebrating its 20th anniversary.

Festivities are planned throughout the weekend at the Women in Military Service for America Memorial in Arlington. The memorial is located next to Arlington National Cemetery but is not part of the cemetery itself.

A key feature of the memorial is a registry that seeks to include information on the service of all 3 million women who have served in the U.S. military. So far, though, the registry includes fewer than 270,000 veterans.

The memorial is funded through a private nonprofit, and supporters say its future is at risk. A fundraising campaign by a group called AcademyWomen has raised more than $110,000. The goal is $1.5 million.