SWAN SONG is a good choice and an enjoyable read. Don't plan on finishing it in one sitting though. Another good McCammon choice is BLUE WORLD, a compilation of short stories including the BLUE WORLD novella. Within is YELLOWJACKET SUMMER, a particularly nasty tale.
I realized after you posted that I have a copy of MOUNTAINS on my computer. Hoping to dive into that one soon. Glad you brought it up.
-------------------- "Thou shalt not be afraid for the terror by night; nor for the arrow that flieth by day;
Nor for the pestilence that walketh in darkness; nor for the destruction that wasteth at noonday." -Psalms 91:5-6