Preheat oven to 350 degrees.
Place mushrooms in a large bowl; drizzle with olive oil and season with salt.
Evenly spread mushrooms in a single layer in a shallow glass baking dish. Transfer to oven and bake, tossing with tongs every 5 to 10 minutes, until dry and crisp, taking care not to burn. Remove from baking dish; mushroom "bacon" may be used hot or at room temperature.