LiDAR imagery does not extend all the way up to Glacier, Washington. As noted in my last post, the Church Mountain Landslide fills the valley floor of the North Fork Nooksack River near Glacier.
DEM (digital elevation model) of Church Mountain Landslide
Summit of Church Mountain is on the upper left
Lumpy area in lower center filling the valley is the thicker part of the slide deposit
The slide deposit extends nearly all the way to the left edge of the image
Note the change in image sharpness with LiDAR DEM on the left half
The Church Mountain slide is absolutely huge. Not to take anything away from the Church Mountain landslide, but the petty side of me has to point out that the Church Mountain landslide is not the largest landslide in the United States or even Washington State. The Sanford Pasture Landslide west of Naches, Washington is substantially larger. A very small secondary portion of this landslide collapsed a few years ago and blocked the Naches River.
DEM of Sanford Pasture Landslide west of Naches
USGS topo map of Sanford Landslide
Aerial of Landslide
DNR images via http://slidingthought.wordpress.com/2009/10/22/527/
A final note: Sanford is not the Washington State champion; there is an even a bigger landslide south of Wenatchee.