The cap of Thaxterogaster oregonensis starts out light purple with an orangishcenter. As the mushroom getsolder, the center becomes yellower and the rest of the cap becomes less purple. It can be convex, conical, umbonate, or flat. It is about 2-4 centimeters in diameter. The stipe is about 3-9 centimeters long and 4-10 millimeters wide. It can be purplish or grayish. The gills are adnexed and start out purplish, becoming grayish and eventually brown.