Choose the path for your walkway. Sit in the yard and sketch possible shapes and lengths or walk the area to determine the beginning, end and course in between. Space the walkway at least 4 feet wide so two people can walk side-by-side. Use landscaping paint or two ropes to outline the area.
Excavate the river walkway path with a shovel until it is 6 inches deep to remove root systems. Press a tamping tool against the soil to pack it down.
Set weed screen or landscape fabric over the dirt and secure it with spikes in each corner. The fabric prevents weeds from growing through the rocks.
Pour river rocks over the site until it is about half-full. Tamp the river rocks to compact them together so the bottom rocks form a strong support base, preventing the surface from shifting.
Fill the remaining expanse with river rocks and rake them so they are even. Tamp the entire surface down until it resists pressure.