Vine Maple (Acer circinatum) is an important forest understory plant in the Pacific Northwest. Where it is exposed to direct sunlight, it turns vivid reds and oranges in the fall. Where it is shaded, it turns yellow. Where it grows in partial shade it can form dense, sprawling clumps with dozens of small trunks. Where it grows in brighter sun, it tends to have fewer, thicker trunks and to be more upright.
In this picture, the green leaves and the red leaves are Vine Maple. Most of the yellow leaves are Bigleaf Maple.
Vine Maple is an exceptionally fine landscaping plant. It is readily available in better Pacific Northwest nurseries. Many of the plants sold regionally are collected in the wild by permit along power line right-of-ways where thay would otherwise be destroyed by periodic brush clearing.