First yellow flower - Fritillaria pudica
Second yellow flower is definitely an Erythronium, most likely grandiflorum -
http://www.montana.plant-life.org/species/erythro_gran.htm
I'm hopeless at bugs, but your beetle looks like a ground beetle, a garden-friendly predator of slug eggs -
http://insects.about.com/od/beetles/p/carabidae.htm
April 19, blue flower, looks like a viola
April 21, purple flower, Dodecatheon, not sure which species, common name shooting star
April 22, little white flower, Lithophragma, woodland or prairie star
April 27, white flower, Trillium
April 28, shrub, looks like an Amelenchior, common names serviceberry or saskatoonberry or shad berry - fruit is edible, pectin source for making jam/jelly with tastier fruit
April 29, yup, Calypso bulbosa
Great
fence, I'm jealous!