Birch Landscape watercolor painting - Underpainting exercise

The above watercolor is the result of first doing a underpainting using Burnt Umber and then adding watercolro layer after layer on top.  It was a fun exercise and although it took me twice the length of time to finish the painting, I think I have accomplished what I have started out to do.  It is important to leave some of the areas blank so that watercolor can be easily on top.  Most of the watercolor paint I put on at this stage are pigments right out of the tube.  It gives the painting a fresh and brillent feeling of color and it have a better coverage of the Burnt Umber underpainting under neath.