Acer cascadense is an extinct maple species in the family Sapindaceae described from a series of isolated fossil samaras.

[2] In the descriptive paper naming T. postnastae Manchester et al reported that radioisotope dating of plagioclase crystals collected by Robert Rosé from the fossiliferous horizon of the Moose Mountain flora had been performed.

Using crystals obtained from tuffaceous sandstones, Argon–argon dating provided an age of 14.91 ± 0.23 Ma placing the flora as Middle Miocene Langhian stage.

[2] The specimens were studied by paleobotanists Jack A. Wolfe of the United States Geological Survey, Denver office and Toshimasa Tanai of Hokkaido University.

The etymology of the chosen specific name cascadense is in reference to the type locality, known at the time as the Cascadia flora, which is in the Northern Oregon Cascade Mountains.