This is the sort that made it to the shelf of a drug store prior to about 1988. The blurb on the back told of dwarves hiding underneath the Canadian tundra, and an enslaved man that they rode as their steed.
This definitely isn't a classic, just from what I remember of it. The dwarves have world domination plans or something like that, but I never read the entire novel.
Got it! Earth Lords (by Gordon R Dickson) - I used to keep track of every book I read, and I guess it came in handy this time. :-)
Deep in a hidden labyrinth beneath the Canadian wilderness dwell dwarfish Earth Lords and Ladies who ride humans like horses - and plot the final downfall of mankind.
Bart Dybig is a "Steed", but one gifted with mental and physical abilities unsuspected by those who have enslaved him. Soon, he vows, he will surprise the Lords and escape to the world above - if there's a world to go back to.
For the Earth Lords are building a doomsday device of unimaginable power to completely destroy mankind. Only Bart and his strange heritage can stop them...
