QUAINT is the prose that issues from Jubal Sackett, narrator and title character of Louis L'Amour's Sackett family historical saga #18: Like Tonto quoting Tennyson. Or maybe Tennyson quoting Tonto. Stark and black are the tall trees in the Tennessee Valley, where the story opens at the beginning of the 18th century. Long sits Jubal by the fire speaking with the old Ni'kwana. This sage asks him to go find the Natchez princess Itchakomi, who is wandering somewhere between the Mississippi and the Rocky Mountains.

That might sound like a pretty large spread of questing-ground, and thus a tall order. But this is a Sackett, and Jubal goes right to where she i, a couple of thousand river miles away, pausing only long enough to kill a panther with a knife while recuperating from a broken leg, to adopt a pet buffalo bull, and to win a few skirmishes with the various Indian tribes that cross his westering path. His sidekick is the stealthy Kickapoo, Keokotah, a stereotypical native American.

Low and gray are the clouds above the hidden Rocky Mountain valley where Jubal and Itchakomi and a handful of her tribesmen then hole up for the winter, hiding from "the fierce young man Kapata, with an accent on the first syllable." Kapata is fierce and hostile because he wants to marry Itchakomi and make her an obedient squaw. And she is too good for that; she is a Sun Princess.

Jubal, one of the three eldest sons of the patriarch Barnabas Sackett of other L'Amour novels, has thus preceded Zebulon Pike by more than a century up the Arkansas River to the foothills of the Sangre de Cristo Range, which should satisfyhim greatly, as his one stated desire in life, repeated in every lull, is to set foot where no civilized man has ever gone before. His wandering feet are annoyingly hobbled, though, by his responsibility and his burgeoning love for Itchakomi, by swarms of dread Comanches, by Kapata, and by squads of mail- clad Spanishmen who want to procure the princess and make her into something even less than a squaw. Jubal has to fight them all, over and over. And as if that weren't enough fighting, he even runs up against a wild and wooly mammoth, which is so mighty that he needs the help of his pet buffalo bull to kill it.

This rousing saga marks the silver anniversary of the Sackett novels and kicks off the reissue of the first 17, of which more than 30 million copies are already in print -- which, if laid end to end, would reach much farther than Jubal Sackett travels in this book. L'Amour says he has lately found himself drawn to the early Sackett generations, and promises that forthcoming volumes will deal with the Sacketts' roles in the Revolution and the Civil War. We might expect these soon: L'Amour is the fastest pen in the West. His previous fiction book titles number 91 (at the time this sentence is being written), and each has become a million-copy bestseller.

THE REASONS for L'Amour's mass appeal are easy to see in this fantastic adventure story. When Jubal Sackett lets L'Amour do the talking, the prose is brisk and clear. With a few plain word-images, L'Amour can evoke the change of seasons in the mountains, the blaze of sunlight on a rapid river, the vast views of the high plains, the timelesss spookiness of a burial cave, the movements of a hunted animal. Only a true outdoorsman can describe the West like this.

He is also a master of suspense; always there are at least two or three enemies lurking out there, and they can be depended on to leap into the firelight before the reader has caught his breath from the last narrow escape.

Another key to his popularity is his wholesomeness. His characters are perhaps the only frontiersmen who don't cuss. The only bodily functions they engage in are the chewing of jerky and the healing of wounds. As for sex, in one impassioned love scene, Jubal and Itchakomi actually hold hands in the shadows. But this is after they are married.

There is, of course, violence aplenty, but it is not gratuitous violence. It is always the war for survival, and L'Amour narrates it so that the reader feels his own arm tense to strike the righteous blow.

The reader can also learn much lore from a L'Amour novel: That there were repeating pistols even in the flintlock age. How to build shelters, even forts, in the wilderness. How to overawe the natives with the "great medicine" of technology.

To some, the greatest appeal of this particular Sackett novel will be its hints of ancient wonders, of old tribes and lost races. L' Amour does not believe that American history began as recently as the schoolbooks told us it did. He has researched the venerable legends -- of Madoc the lost Welsh explorer, of possible Phoenician or Carthaginian trade with North America's Indians, of the lost race of bearded men whose ghosts reigned in Kentucky, of the giant Ice Age mammals which even Jefferson believed still walked the unexplored West. A hundred years after Jubal's fictitious trek, Jefferson told Lewis and Clark to keep an eye out for mammoths and giant sloths on their journey to the Pacific. Indians as late as the early 19th Century reported having seen mammoths and hunted them, and L'Amour, like Jefferson, chooses to give them credence.

The "New World" is an older world than we have been conditioned to believe, and L'Amour does his readers a service by recalling ancient mysteries to bemuse them.