You’re marvelous! I’m guessing sweet gum too, since this is a lovely amber color. It’s all through the house, which is amazing, and more amazing, no one painted over it, which was a trend at some point in these houses and in this neighborhood.

About the gum: unless you know more than you said, it’s probably one of the North American gums, sweet gum (Liquidambar styraciflua) or black gum (Nyssa sylvatica) – and don’t they both have lovely names? I’d guess sweet gum, as it’s supposed to have very nice walnut-like wood. Neither species makes it into Montana according to plants.usda.gov but it’s a much shorter haul than trying to get a tropical wood.

(I’m a botanist, not a wood-worker.)