Unusually for a poet, Francis Harvey has insider knowledge of the banking system, and of Bank of Ireland in particular.

There was the branch in Ballina, for example, that managed to operate without a phone. "It was the first branch I worked in," says Harvey, who was born in Enniskillen in 1925, "and the manager didn't like the phone. When they'd call up from College Green about a reference or something, he'd send the youngest employee across the street to the shop to take the message."

Then there was the branch where the manager liked to take his ease. "He'd sit by the turf fire, warming his testicles and listening to the clerks gossiping about girls. One day, the Bishop of Derry drove up in his Austin Princess and walked right into the office without knocking, and in a minute the manager was down on his two knees, with his fag burning a hole in his trouser pocket that had to be put out in a glass of water."

Harvey spent his working life in the bank, but he had a secret life as well: he wrote. Not that it was all that secret. His prize-winning play Farewell To Every White Cascade, about a farmer deprived of his land and living when the Ballyshannon water scheme was set up, dealt with a theme so universal that it was broadcast not only by RT╔ but also by the BBC and countless European radio stations.

One of his poems won first prize at the Yeats summer school, and his marvellous poem Heron won the Guardian/World Wildlife Fund prize in 1989, the year Ted Hughes was judge.

"There's quite a lot of people like that poem," he says, and it's not hard to understand why. Here is one verse:

He alights: furls his wings like a wet umbrella, settles,

Rapt and murderous,

Drying out in the wind and sun on the edge of a tarn

Or hunched over a pool in a burn pretending he's

A blind one-legged beggarman or a mystic communing with God.

Too late, too late for the fish or the frog when it realises

He's not an old cod.

Harvey, whose new collection, Making Space, is published this month, draws his inspiration from the people and landscape of Donegal, where he has spent most of his life. In the company of Gerry Moriarty of this newspaper, he has walked the hills, glens and islands of the county.

There was one day when they headed off to climb every peak in the Blue Stacks between sunrise and sunset. Agnes, Frank's wife and no mean walker herself, drove them to their setting-off point at 4 a.m. "It was a glorious day," says Moriarty, "and we'd have climbed every peak except that we had to rescue a ewe that had fallen into a bog hole."

Moriarty was then the literary editor of the Donegal Democrat and ran a page called The Rat Pit, after one of Patrick MacGill's novels. But while economic pressures forced MacGill to leave his native county, Harvey stayed and has a lifetime's work to show for it. He was never drawn to Dublin and the literary razzmatazz and feels that academics have had a stranglehold on poetry. The writers came to him, though. Brendan Behan was a regular visitor and, after him, Beatrice. Ben Kiely, too.

His poetry is about farm gates, lichen on Slieve Toohey, foxgloves, islanders and solitary farmers, and it comes in the quiet of reflection, after the walk is done, the homeward journey completed, written in his book-lined study in Donegal town, where he can talk to himself about Wittgenstein, philosophy and death - his own and others'.

"Some of my poetry comes easily, but mostly it's hard work," says Harvey. "You can't worry a poem into existence. The greatest satisfaction comes when I think, well, I can't do anything more to that, and then you need a treat - which was a drink, in the old days."

Sometimes, he takes a notebook with him on his walks, but more often not. "I'd notice him looking at the flow of water or the flight of a bird, and then drumming with his fingers to get the metre right," says Moriarty.

There are terrifying poems in the collection as well, including one about a child being raped by her father, "her arms stretched out under him like a cross".

And there are the two religious traditions he gives voice to, for his Protestant father, from Enniskillen, eloped with his Catholic mother, from Ballyshannon. It was a sacristy wedding. "Neither family approved," says Harvey. When his father developed cancer and went for treatment to Dublin, where he underwent a conversion to Catholicism, the Enniskillen relatives shook their heads, for he'd gone down a Protestant and come back a Catholic. The Jesuits got him, they said.

Harvey was only six when his father died - the loss is a recurrent theme in his poems - and his mother brought the children back to her family. "My maternal grandfather was a cattle man and I'd walk the fields with him. He was a great influence. When he grew old, he'd recite Allingham to me while I'd have the job of looking out the window and telling him who was going up and down the street."

His first poem, about potato-digging, was published when he was 16, in the Weekly Independent, which was also the first to publish Patrick Kavanagh. By then, he was reading Milton and Wordsworth. By the age of 20 he'd read the whole of Dickens. "My mother was very generous: she'd let me lie in bed half the day, reading."

After a stint at University College Dublin, reading medicine, he moved to the bank, settling eventually in Glenties with Agnes and their five daughters. "Banking never suited him," says Moriarty, "and when computerisation came in, that was it. Frank was interested in people. He much preferred talking to some old farmer that came into the bank than working with figures."

Harvey saw the writing on the wall. "The bank was glad to see me go. They didn't like the way I was always writing letters to The Irish Times about this and that."

Brought up a Catholic, now an agnostic - and in his poetry an animist - the old Catholic fear of what the priests called sin surfaces in the new poems:

They flushed sin from the coverts of my soul with fear.

Where was love hiding if it wasn't here?

If you've never walked the empty hills of Donegal, Harvey's poetry will take you there - but be warned: you'll be treading on somebody's heart:

Pull up your car for a moment, stranger,

look hard at that broken discarded man

who totters on sticks between the mountain

and the sea. Once he was strong and upright

as you and me till scraping in the scraw

of his few acres here at home or tatie-hoking in an icy Scottish mist from dawn to dusk took all the sweetness

out of him and left this husk.

Making Space is published by The Dedalus Press (£7.95/€10.10)