The U.S. Army Corps of Engineers, Seattle District, is seeking sources to operate a smolt trap on the Green River in King County, Washington, to monitor the biological outcomes of flow management at Howard A. Hanson Dam. The contract will be a firm fixed price award, with a base year and four option years, and trap operations will occur between February and July. This is a market research notice only, not a solicitation, and no reimbursement for response costs will be provided. Responses are due by 12:00 PM PDT on 15 June 2026, and interested firms must be registered in SAM.gov. No budget amount is specified.