Here's a synopsis:

Beyond the Cascade is a marriage between Gulliver and The Celestine Prophecy, between Robert Ruark, or Papa Hemingway, and Bridge Across Forever. It goes further than these in some dimensions, if less far in others, and it could be thought of as an educated Jennifer Livingston Seagull. Except that Beyond the Cascade is not about birds. It is about humans. Human souls, human language, minds and hearts, and the battles they cause. It offers its own unique perspective in the weaving of these things. It is, as far as categories are concerned, a "literary and spiritual adventure novel" focusing on the soul of a woman. It is sometimes ungentle, but it is never unkind. The tale is richly featured with sub-plots and explorations into linguistics, anthropological quirks and some fine cuisine. It even explores, in the course of its development, the mystic legacy of the Grail legends beyond the Arthurian clichés and other distortions.

Beyond the Cascade follows the adventures of Suzannah Grant, an unstoppable American Alpha Chick in her mid-thirties who is beginning to reach the pinnacle of success in her career as a linguistic anthropologist, and who finds herself unexpectedly hitting a black, cold wall of clinical depression. Her usual solutions to hurdles do not avail, and her search for medical help produces nothing of value. Her psychiatrist, running out of other solutions, sends her off with the mandate to "learn new things". While fumbling around trying to do so, she finds herself picking up an antique journal from a Victorian explorer in which she encounters a description of a remote tribe whose unusual culture and language set off distant bells in her foggy thinking.,

Picking up the threads of the explorer's trail, she finds herself being more and more determined to resolve the mystery of the people of the fabled Cascade, their culture and their mysterious atypical language. Exhuming long buried manuscripts in old university archives, digging into legends obscured by centuries, and finally throwing herself into a full-blown trek into the hinterlands of Africa, she finds herself in the hands of two remarkable men: a guide called Muhaybee and a leathery ancient witch named Doc. The travails and discoveries of her path ultimately bring her to the Cascade, and a great deal further, leading to dramatic changes in her mental perspective and an explosive intensely spiritual culmination which goes beyond the expected and the known to a bit more than that.