This is a small forest floor flower often found in conjunction with the Oregon Oxalis. The plant is small usually not over 2 or 3 inches high with the flower pedals 7-10mm long. It is found on the western slope of the Cascades and in the coast range from British Columbia to California. It flowers in the fairly early spring being out at the same time as the Trillium.
This is a flower that you are more likely to step on than enjoy, as it is so small that it often goes unnoticed and the real beauty of it as shown here is probably better seen in the photo than in the real life unless you are comfortable with your eyes a few inches off the ground. This was shot at f/27 with a ringlight type flash and a 50mm Macro lens with a ND4 filter as flash automation was not available on the Pentax hardware I used.