The Catechism in Questions & Answers

3. How does God reveal Himself in nature?

God reveals Himself in nature as the Creator: in the existence of the universe, of mankind, and of animals and plants.

“He waters the hills from His upper chambers; the earth is satisfied with the fruit of Your works. He causes the grass to grow for the cattle, and vegetation for the service of man, that he may bring forth food from the earth.”
Psalm 104: 13-14