Its called canvasboard and has been used for years for classroom work !! It has a canvas-like texture on the front and can be found at most art or department stores if they have a craft section !! When I taught classes that is what we used since it typically comes in a three pack and we didn`t have to run to the art supply stores so often !! This could be gouache or acrylic or oil since either would be acceptable with canvasboard !! Your pic almost looks like some scenes from Yellowstone area !! It could have been done from a calender pic or on location !! No real way to know !! Canvasboards they sell now have a place on the back for name, location and date !!
