|Bigleaf maple foliage|
|Section:||Acer sect. Macrophylla|
Big Leaf Maple can grow up to 48.10 metres (157.80 ft) tall, but more commonly reaches 15–20 m (50–65 ft) tall. It is native to western North America, mostly near the Pacific coast, from southernmost Alaska to southern California. Some stands are also found inland in the foothills of the Sierra Nevada mountains of central California, and a tiny population occurs in central Idaho.
The bigleaf maple has the largest leaves of any maple, typically 15–30 cm (5.9–11.8 in) across, with five deeply incised palmate lobes, with the largest running to 61 centimetres (24 in). In the fall, the leaves turn to gold and yellow, often to spectacular effect against the backdrop of evergreen conifers.
In spring, bigleaf maple produces flowers in pendulous racemes 10–15 cm (4–6 in) long, greenish-yellow with inconspicuous petals. It is hermaphroditic, bearing both male and female flowers in each raceme. The flowers appear in early spring, before the leaves.
The fruit is a paired winged samara, each seed 1–1.5 centimetres (3⁄8–5⁄8 in) in diameter with a 4–5-centimetre (1+5⁄8–2-inch) wing. Bigleaf maple begins bearing seed at about ten years of age.
Bigleaf maples can form pure stands on moist soils in proximity to streams, but are generally found within riparian hardwood forests or dispersed, (under or within), relatively open canopies of conifers, mixed evergreens, or oaks (Quercus spp.) In cool and moist temperate mixed woods they are one of the dominant species. It is very rare north of Vancouver Island though cultivated in Prince Rupert, near Ketchikan and in Juneau.
The winged fruits are eaten by squirrels, and by grosbeaks in the winter.Deer mice have been observed consuming bigleaf maple seeds in the spring in the Sierra Nevada. The foliage is browsed by ungulates such as black-tailed deer, mule deer, elk, and horses, as well as by mountain beavers and other rodents. 
A western Oregon study found that 60 percent of bigleaf maple seedlings over 25 cm (10 in) tall had been browsed by deer, most several times.
Bigleaf maple is not considered to be fire-resistant due to its thin bark, although large trees with thick bark may survive moderate-severity fires. However, along with red alder, bigleaf maple often dominates early postfire succession in Douglas-fir forests, and fire can increase its presence in a forest.  It spreads and grows vegetatively from cuttings and stumps of any size in a prolific manner. 
The wood is used for applications as diverse as furniture, piano frames and salad bowls. Highly figured wood is not uncommon and is used for veneer, stringed instruments, guitar bodies, and gun stocks.
The wood is primarily used in veneer production for furniture, but is also used in musical instrument production, interior paneling, and other hardwood products; the heartwood is light, reddish-brown, fine-grained, moderately heavy, and moderately hard and strong. Native Americans used the wood to make canoe paddles.
Maple syrup has been made from the sap of bigleaf maple trees. While the sugar concentration is about the same as in Acer saccharum (sugar maple), the flavor is somewhat different. Interest in commercially producing syrup from bigleaf maple sap has been limited. Although not traditionally used for syrup production, it takes about 40 volumes of sap to produce 1 volume of maple syrup.
The current national champion bigleaf maple is located in Lane County, Oregon. It has a circumference of 11.8 m (38.6 ft)—or an average diameter at breast height of about 3.7 m (12.3 ft)—and is 36 m (119 ft) tall with a crown spread of 28 m (91 ft). The previous national champion is located in Marion, Oregon, and has a circumference of 7.7 m (25.4 ft)—or an average diameter at breast height of about 2.5 m (8.1 ft)—and is 27 m (88 ft) tall with a crown spread of 32 m (104 ft).
In May 2018 the oldest two Oregon Maples in Europe, 175 years old, were removed from Trinity College Dublin, Ireland: the first had an interior which was beginning to rot, and it fell after inclement windy weather. The second, also infected, was cut down as the same fate was expected. Both were in the adjoining grassy area which was originally the cemetery of All Hallows and is now the Front Square of TCD.
- 'Mocha Rose' — foliage in various shades of pink over growing season; red flowers
- 'Santiam Snows' — green leaves speckled with white
- 'Seattle Sentinel' — upright, columnar plant habit
Moss on Bigleaf maple in Hoh Rainforest in Olympic National Park, Washington
Bigleaf maple in the McKenzie River valley in western Oregon
"WORLD'S LARGEST BIGLEAF MAPLE" IN ENGLISH CAMP on San Juan Island, Washington
Fallen Acer macrophyllum leaf in fall near Cashmere, Washington
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- photo of herbarium specimen at Missouri Botanical Garden, collected in Yolo County, California, in 1903