This little guy is a monarch butterfly.
Monarch butterflies embark on a great migration annually - flying from Canada to Mexico, and sometimes even farther! This means they have to stopover in the United States along their journey. The complete round-trip migration actually takes four monarch generations to complete - one generation to fly down, and three to fly back!
Monarch butterflies are facing decline due to the loss of their host plant, milkweed. Host plants are the only plants certain butterfly species can lay their caterpillar eggs on. Now that spring has finally sprung - once it looks like the last frost of the season is behind you, consider planting milkweed in your area!
Maybe you don't have monarchs visit your area much - that's okay! Instead, learn about the types of butterflies that you DO have in your area, find out what some of their host plants are or other butterfly friendly plants, and plant those instead! Mature forests/trees are also important to monarch butterfly migrations. They will roost by the thousands on large trees to stay warm and until their wings have dried from the overnight dew before continuing on their journey.
p.s. Milkweed is poisonous, therefore when monarch caterpillars eat them, they and the mature butterfly are also poisonous! This is why the butterfly is bright orange - as a warning sign to hungry birds!