The entire of the old RMA was included in the remediation effort. On January 21, 2003, the Environmental Protection Agency (EPA) certified as ready for use, and this acreage was turned over to the USFWS. Another were certified clean on January 15, 2004. This allowed USWFS to formally open the Rocky Mountain Arsenal National Wildlife Refuge on April 2, 2004. At that time, walking trails gave guests access to about of the refuge, and buses allowed visitors to tour another . EPA released another on July 31, 2006. The remaining were declared contaminant-free and turned over to the refuge on October 15, 2010. The total cost of the cleanup was $2.1 billion.