RE: #28 ??? One must also wonder the extent to which the LIA slowed Spanish settlement of NW Mexico and what is now the US SW. You can clearly see where the true deserts of the time were, their extent is equivalent to the current ???dry tree line??? ??? for example, as of about 1600, places where there is now greater than 10 in of rain per year, but no trees, such as many parts of the coastal rang