In 1997, Congress provided much-needed organic legislation with the passage of the National Wildlife Refuge System Improvement Act. This legislation amended the National Wildlife Refuge System Administration Act of 1966 and provided significant new guidance for the management of the Refuge System. It provided a new statutory mission statement and directed that the Refuge System be managed as a national system of lands and waters devoted to conserving wildlife and maintaining biological integrity of ecosystems. The law also clarified management priorities by declaring that certain wildlife-dependent recreational uses are appropriate activities on refuges, strengthened the compatibility determination process, and required the Service to undertake comprehensive conservation planning for each refuge. In 2006, a bi-partisan group of 100 members of Congress formed the Congressional Wildlife Refuge Caucus to further the needs of the Refuge System with a unified voice.