ST. LOUIS -- Leaders of a construction project designed to better link downtown St. Louis and the Gateway Arch say they have raised more than $178 million in private donations.

The CityArchRiver 2015 coalition announced on Friday it has received corporate donations of at least $10 million each from charitable trusts of local companies Emerson and Monsanto. Project leaders hope to have the fundraising campaign complete by 2015, the 50th anniversary of the Arch. They want to raise another $72 million from private sources.

The project's original complete date of 2015 has since been pushed back a year. The $380 million in expected improvement costs includes $90 from a bond measure approved by city and county voters in April.

Broadcaster Joe Buck presided over the announce at downtown's Ballpark Village.