These terraces represent levels where the stream paused in its downcutting and cut sideways for awhile. No exotics have yet appeared in this plant community. Wildflowers include the prominent phlox, penstemon, and lupine. The brittle prickly pear and spiderwort cactus are found here too. At higher levels in the terrace community, slightly steeper slopes and shallower soils cause some change in this mixed-grass assemblage.
Lupine disappears, and common pricklypear becomes the only cactus.
In this community is found the yucca, its flowers a beautiful soft yellow in season and its spiny leaves painful at any time of the year. The yucca moth, often seen flying around the yucca seed pods, lays eggs in the plant's lemon-sized fruits. Inside the fruit are long rows of flattened, wedge-shaped seeds. When the yucca moth eggs hatch into caterpillars, they eat their way through the seeds, killing them. On the high bluffs and overgrazed terraces is the fifth community, the short grass.