No other maple in North America grows leaves this large. A bigleaf maple leaf can span a foot across, with five deep lobes, and a broken leaf stalk oozes milky sap. The tree is big too, commonly around 50 feet tall and sometimes much taller, which makes it the largest maple species on the continent. In spring it hangs out long clusters of small yellow flowers, and by fall its branches carry pairs of winged seeds with bristly seed cases.
What really sets it apart is what grows on it. Its limbs carry a heavier load of moss than any other tree in the Pacific Northwest, and mosses, liverworts and ferns drape its branches and fill the crotches between them. That hanging garden, plus the seeds and leaves, supports a long list of wildlife. Deer, elk and mountain beavers browse it, squirrels and evening grosbeaks eat the seeds in winter, and brown creepers and pileated woodpeckers forage or nest in it.
Bigleaf maple is a tree of the lower slopes. Look for it along streams, in canyons and in moist woods of the Cascade foothills, mostly below about 3,000 feet. Its thin bark gives it little protection from fire, but when fire or cutting kills the trunk it sprouts back fast from the base, sometimes growing 10 feet in a year.
How to identify it
Leaves grow in opposite pairs and are much larger than any other maple's, often 6 to 12 inches across, with five deep lobes and milky sap in the leaf stalk. Fruits are paired, winged seeds with a hairy seed case. Mature trees are large, usually 40 to 100 feet in height, and their trunks and limbs are usually thick with moss.
Look-alikes
Vine maple, common in the same forests, is a shrub or small tree with nearly round leaves only about 1 to 2.5 inches across and 7 to 9 lobes. Thimbleberry has a similar leaf shape but is a shrub with leaves set one at a time along the stem and red fruit instead of winged seeds.
Habitat
Moist woods, canyons and streamsides in the Cascade foothills and lowlands, up to roughly 3,000 feet above sea level in Oregon and Washington. It grows best on deep, moist soils near water.
Sightings in the forest
698 research-grade sightings in Mt. Hood National Forest on iNaturalist, most recently on October 31, 2026. See them on iNaturalist →