The flower is:
Erythorium americanum (Trout Lily) can be found in rich moist woods and typically blooms in April, though like everything else, it is a little early this year. The similarity in the mottled leaf to the scales of a trout is how the plant got it's common name. This small unique lily is pollinated by ants, and is a pleasant, colorful surprise in the spring woodland garden. It takes seven years for a pollinated seed to become a mature plant, and only plants with two leaves will flower.
Look for these flowers in a woodland near you while they are still around! These can also be great additions to a woodland garden for some great spring color. They are not super aggressive, so be careful about what other plants you put in an area where you put the trout lily.