Western larch is native to a restricted area in the western Rockies in North America. In Finland it grows successfully only in the richest and warmest sites in the south of the country.
It is most easily distinguished from other larches by its cones, where the seed bracts extend beyond the cone scales. It is narrower in habit than the other larches and large-growing, achieving heights of 40-50m.
Growing western larch at Mustila has proved difficult. Of older plantings there is only a single specimen which can be described as a proper tree, on Pähkinärinne (Hazelnut Slope). More recent trials from the 1980s seem to indicate that it might be possible to find provenances suitable for Finland.