Prior to the launch of the Delivering for America plan, the U.S. Postal Service used Surface Transfer Centers to distribute, consolidate, dispatch, and transfer all mail classes within the surface network. They also served as a concentration point for consolidating mail from under-utilized surface trips. In September 2024, the Postal Service transitioned to the use of RTHs. RTHs are intended to decrease the number of mail separations and fill containers quickly during processing to expedite getting mail onto trucks and out for delivery to customers.

As of March 2025, 18 RTHs were active nationwide. While the Postal Service indicated that work handled at RTHs would be insourced, some RTHs, such as the Denver RTH, continue to be operated by contractors rather than Postal Service employees.

To support the RTH initiative, the Postal Service converted the Denver Peak Annex into the Denver RTH, which began operations in October 2024. The Postal Service modified its existing contract with the contractor responsible for managing the peak annex to facilitate this transition. The updated contract incorporated provisions that aligned the facility’s operations with RTH standards. Several contractual modifications were made to support the facility’s transformation, which included new responsibilities for the contractor to aid in RTH operations and language specifying that the Postal Service would insource the work before the end of 2025.