My terrain related tutorials in 3D World mag: Create LiDAR Based Landscapes (#242) | Discover Houdini's terrain toolset (#243): https://www.creativebloq.com/how-to/build-terrain-in-houdini-17
Alaska Blue Lake mountains, based on DEM but with elongated heights (render of #242)
Eroded the same location in Houdini (a step image in #243)
The Blue Lake (which is sometimes quite turquoise thanks to the suspended slit in the water which comes from the rock grinding glaciers)
The geometry from top view
With quite proper (and slow) raytraced volumetric effects (separate volumetric containers for different wavelength light scattering)
Definitely not Alaska, but raw point cloud render with simple volume and some paintover...
Elon's favourite. Official DEM from NASA (resource link in the description)