Where do desert birds get water? That question explains why so many desert birds are found near riparian areas(wet places like springs).
In the forest at high elevations you can expect some morning moisture but nothing like the fog or dew of an eastern forest. These are desert forests too. Each type of bird has its own particular way of getting water that it needs. Most are very efficient at using water in their bodies too. Their droppings are rarely as wet as birds near the sea or even in forests where water is plentiful. They conserve water internally.