sentences:  Built in
  1936-37 by the United States Forest Service
  and the Works Progress Administration
  (WPA), the observatory reflects the rustic
  style of architecture found in public
  buildings throughout the national parks and
  forests.It is marked by simplicity and
  craftsmanship, appearing to grow out of the
  earth rather than intrude upon it.Basalt
  stones were selected from the mesa and
  carefully fitted together to form the walls
  and terrace.