Terragen 4.4.44, Pixelmator Pro 1.7
Used digital elevation model for Crater Lake Nation Park, Oregon, from the USGS 3DEP LidarExplorer database (DEMs) here: https://prd-tnm.s3.amazonaws.com/LidarExplorer/index.html#/.
Reference photo here: http://www.runladylike.com/wp-content/uploads/2016/07/IMG_2247-1024x768.jpg
Crater Lake reference photo.
http://www.runladylike.com/wp-content/uploads/2016/07/IMG_2247-1024x768.jpg