This is 3 exposures blended together using my advanced Photoshop tonality control and multiple exposure blending techniques. I produced a video detailing these techniques, it's available here: www.zschnepf.com
This was taken while teaching a 3 day workshop at Crater Lake National Park with fellow Photo Cascadia Member David Cobb. Big thanks to David for having me as co-instructor. We were treated to some fantastic conditions and light, especially on Sunday night on the rim.
Edit: A few people asked about the light on the wood. It's from the clouds reflecting the sunset to my right out of the frame. This sky was 360 degrees of sweet light.