CityArchRiver 2015 is a public-private partnership formed to fund and coordinate the design and development of the project. Private donors funded the entire cost of the international design competition, Framing a Modern Masterpiece: The City + The Arch + The River, and continue to fund design costs for the project. In December 2011, more than $57 million was secured through federal, local and private sources (USDOT, MoDOT, and CityArchRiver 2015 Foundation) to completely fund construction of the Park Over the Highway and I-70 connections associated with the project. Great Rivers Greenway has committed an initial $18 million to the new riverfront design. An additional $250 million in private gifts and grants will be raised to help fund the $380 million project in Missouri and endowment for the Foundation’s work as a conservancy.
On April 2, 2013 voters in St. Louis County and St. Louis City approved Proposition P: The Safe and Accessible Arch and Public Parks initiative. Revenue from Proposition P will fund improvements to Great Rivers Greenway’s trail system, regional and local parks, and approximately $90 million will be bonded for accessibility, safety, improvements and maintenance for the Gateway Arch grounds public infrastructure. Funding generated from Proposition P for improvements to the Arch grounds and surrounding areas will be administered by Great Rivers Greenway.