The Whitewater River is a popular destination for kayaking and canoeing in the Lance Rosier Unit of the Big Thicket National Preserve in Texas. The ideal streamflow range for this river run is between 200 and 500 cubic feet per second (CFS). The river is classed as a Class II-III, with some rapids and obstacles that can provide a challenging experience for intermediate paddlers. The total segment mileage of the Whitewater River run is approximately 7.5 miles, ending at the confluence with the Neches River.

The river run consists of several Class II rapids, including "Little Niagara," "Snoopy's Fall," and "Beehive." These rapids are created by rocky outcrops and fallen trees, which can provide a technical challenge for paddlers. The river also features several drops, including a 10-foot waterfall that is not suitable for inexperienced boaters.

To protect the natural resources and provide a safe experience, there are specific regulations for the area. Paddlers are required to wear personal flotation devices (PFDs) while on the river and are prohibited from littering or damaging the surrounding ecosystem. Camping is permitted only in designated areas, and fires are prohibited except in established fire rings. The National Park Service also recommends that paddlers check current water levels and weather conditions before embarking on the river run.

In summary, the Whitewater River run in the Lance Rosier Unit of the Big Thicket National Preserve provides a challenging and scenic experience for intermediate paddlers. The ideal streamflow range is between 200 and 500 CFS, and the river is classed as a Class II-III. Paddlers should be aware of specific rapids and obstacles, and follow regulations to protect the natural resources and ensure a safe experience.