IVAN DOIG was first noticed as a writer 15 years ago with ``This House of Sky.'' That reminiscence of the years spent with his widowed father bouncing around ranches and sheep camps in Montana was followed by five more works, including a trilogy of novels about an emigrant Scottish family in the Rocky Mountain West.
Now Doig, one of the most readable and productive writers out of the American West today, has backtracked to his boyhood in the middle of this century when his parents spent World War II working on isolated ranches and at an Arizona defense plant.
As the only youngster among adults, Doig liked to ``prowl with [his] ears.'' The detailed anecdotes, moods, and impressions mentally tucked away during his childhood are put into print here. A historian and former journalist, Doig also includes other details gathered since then from family members and acquaintances. Most important, he draws heavily on letters from his mother to her brother aboard a United States warship in the Pacific - letters he did not see for more than 40 years.
Where necessary, and as a conscious literary device, Doig also draws on what he calls ``deliberate dreams'' (he refers to this as ``a little help from Pablo Neruda''), a construction of events and dialogue based on his best sense of what happened nearly 50 years ago. ``It's the only way I can think of to get at what might have gone on beyond what I can hear and see,'' Doig told this reviewer in 1991.
This means of filling out the story seems legitimate, a reminder of something attributed to novelist Ken Kesey, another writer out of the West: ``Just because something didn't happen doesn't mean it's not true.''
For a good chunk of time, the Doigs lived what was essentially a 19th-century frontier existence in the mid-20th century. For months at a time, their home was a one-room sheep camp high in the Bridger Range of the Rocky Mountains with an outhouse and no electricity except for the occasionally used generator.
Both Charlie and Berneta Doig herded sheep, trapped weasels, looked to other chores, and took young Ivan along on their various adventures. Other strong presences are Uncle Wally, the recipient of Berneta's wartime letters, and Doig's maternal grandmother, who later would become a surrogate parent.
``Gnarled and bent as a Knockadoon walking stick, my grandfather; my grandmother, on the other hand, so sturdy she could carry the rest of us over the Crazy Mountains on her back,'' he writes. ``The hands and arms of Bessie Ringer were scarred from every kind of barbwire work, yet there she sat hooking away at the most intricate of crochetwork, snowflaking the rough rooms of her existence with doily upon doily.''
Berneta Doig's struggle with illness is a thread through ``Heart Earth,'' and the book closes with the death of the writer's mother on his sixth birthday. But the poignancy and sadness are not overwhelming, and one is left remembering the humor and family closeness (quarrels as well as affection), the strength of character and essential hopefulness that have come to be Doig trademarks.