Critical Habitat Designation for Four Endangered Freshwater Mussels

The rule designates critical habitat for four freshwater mussel species under the Endangered Species Act: approximately 599 river miles for rayed bean (15 units), 801 river miles for sheepnose (11 units), 2,425 river miles for snuffbox (38 units), and 1,140 river miles for spectaclecase (12 units), totaling approximately 3,814 unique river miles across 76 units in 17 states. Federal agencies funding or authorizing projects in these areas must now consult with the Service under Section 7 to ensure their actions do not destroy or adversely modify critical habitat. The rule largely follows the proposed designation with minor adjustments to unit boundaries based on public comments, and excludes approximately 10 river miles at Fort Leonard Wood under an INRMP exemption. Since most designated areas are already occupied by the species, the primary effect is adding a critical-habitat lens to existing Section 7 consultations, with incremental administrative costs estimated at less than $630,000 per year.

Affected parties include any federal agency, contractor, or project proponent seeking federal funding, permits, or authorization for activities within designated river segments—from infrastructure projects to water withdrawals to agricultural operations with a federal nexus. Private landowners without federal involvement are not directly regulated, though adjacent activities affecting water quality may face indirect impacts through the consultation process. States with designated units should coordinate with FWS regional offices (Ohio, Illinois-Iowa, Minnesota-Wisconsin) for project-specific guidance.