This is the Official Posting of the Program Solicitation for Little Mountain Testing Facility (LMTF) Progress-Design-Build OT.The U.S. Army Corps of Engineers (USACE), Sacramento District (SPK) is issuing Program Solicitation No. W91238-26-9-A001 as an Initial Announcement for the Little Mountain Test Facility (LMTF) Radiation Research Facility at Hill Air Force Base, Utah. The project will be awarded under the authority of Title 10 U.S.C. � 2808a using a Progressive Design-Build (PDB) Other Transaction (OT) Agreement. The selected Design-Builder will perform Phase 1 Design and Pre-Construction Services, with the potential for Phase 2 Final Design and Construction through modification upon successful negotiation of a Fixed-Price (FP) or Guaranteed Maximum Price (GMP), subject to required approvals and funding availability. The project, classified under NAICS 236210 and PSC Y1AZ, has an estimated Not-to-Exceed (NTE) value of $111.5 million. The new Radiation Research Facility is required to modernize testing capabilities and provide dedicated space for critical equipment supporting the Sentinel weapon system while ensuring uninterrupted testing operations for the existing Minuteman III system. The Government intends to make a single OT award but reserves the right to select, not select, or continue discussions with any Design-Builder at any stage of the solicitation process. Bidding Inquiry System: All questions regarding this Program Solicitation must be submitted through the ProjNet Suite Bidder Inquiry System at https://www.projnet.org/projnet. Solicitation Number: W91238-26-9-A001 Bidder Inquiry Key: DSK6IU-VBHJM5 See all attachments in PIEE.