The Rio Soninho is a river in the Tocantins state of Brazil, specifically within the Jalapão region. It is a headwater tributary of the Do Sono River. The river is known for its clear, crystalline waters and scenic landscapes characterized by several beautiful waterfalls, such as the Cachoeira do Soninho. The area offers a notable rafting experience, with one popular route covering approximately 12 to 13 kilometers over a two-hour descent. This stretch provides excitement and passes through natural scenery that includes native birds. The river is situated near the towns of Ponte Alta do Tocantins and São Félix do Tocantins, which serve as reference points for access. The overall character of the paddling experience is one of adventure through a pristine natural environment, with the rafting descent being the primary documented activity on the waterway.