The Gateway Partnership Act allows the Secretary of the Interior to enter into a one-time agreement, lasting up to five years, with the Gateway Arch Park Foundation, a nonprofit partner organization, to host private events at Gateway Arch National Park in St. Louis, including in buildings like the Arch Visitor Center and the Old Courthouse. Any such agreement must include safeguards protecting the park, such as limits on the number of monthly events, required liability insurance, staffing requirements for public safety, and provisions ensuring private events don't disrupt public access or degrade the park's character. The Foundation would be charged fees to cover maintenance costs, and the government could recover additional expenses like utilities, security, and administrative costs tied to the events. This authority automatically expires seven years after the bill becomes law, and any agreement in place at that time would also terminate. The bill also requires the Interior Department to report to Congress within four years on how the arrangement is working, covering both its operational effects on visitors and staffing and its financial outcomes, while making clear that the Park Service retains its normal authority to host events or issue permits to others.