In spring, the tree produces flowers in pendulous racemes 10–15 cm (4–6 in) long, greenish-yellow with inconspicuous petals.

[10] In May 2018 the oldest two Oregon maples in Europe, 175 years old, were removed from Trinity College Dublin (TCD), Ireland.

[6] It can form pure stands on moist soils in proximity to streams, but is generally found within riparian hardwood forests or dispersed, (under or within), relatively open canopies of conifers, mixed evergreens, or oaks (Quercus spp.

[17] The tree can live in a wide range of habitats, but thrives in fairly well-hydrated hardwood forests, occurring with red alder, black cottonwood, and willows.

[19] Deer mice have been observed consuming bigleaf maple seeds in the spring in the Sierra Nevada.

[20][21] A western Oregon study found that 60% of bigleaf maple seedlings over 25 cm (10 in) tall had been browsed by deer, most several times.

[20] In the wetter parts of its range, such as in the Olympic National Park and lowland forest around Puget Sound, the bark is often covered with epiphytes such as club moss and licorice fern.

[6] Cultivars are plants sourced and/or bred for specific characteristics that are deemed to be attractive and/or commercializable to the mainstream public.

Given the opportunity, cultivars will near-universally cross with their native counterparts, which brings a risk of contamination to local genetic stock that can be a challenge to identify.

Examples of cultivars include: Native Americans grew sprouts from the seeds for consumption, wove baskets from the inner bark, and used the leaves to cover food in cooking pits.

In California, land managers do not highly value bigleaf maples, and they are often intentionally knocked over and left unharvested during harvests for Douglas fir and redwood stands.