This seems to be the original poem.

From Feis na nGleann: A Century of Gaelic Culture in the Antrim Glens by Padraic O'Cleireachain (Ulster Historical Foundation, 2005), page 180:


THE BLUE HILLS OF ANTRIM
Seosamh MacCathmhaoil (Joseph Campbell)

The blue hills of Antrim I see in my dreams,
The blue hills of Antrim, the glens and the streams,
In sunlight and shadow, in weal and in woe,
The sweet vision haunts me wherever I go.

The wind's in the heather of sunny Cnoc-leithid,
And soft thro' the vale of Gleann-seasg hath it played,
O'er young Margie's wemplings and deep Mael's roar,
It croons in my heart, and will croon evermore.

Sliabh Treastain's in shadow, and Gleannan in tears,
Looks sorrowing up at her love through the years,
That sad look at Treastain I cannot forget,
My heart pines in darkness, my lashes are wet.

The sun's on Gleann-duinne and old Sliabh-an-air
Thinks only of peace now and never of war,
My heart's in the sun now, it sings like a bird,
Of question or quarrel it never had heard.

O'er lone Luirg-eadain the dim shadows creep
And Cois-abhann-dalla is silent in sleep,
As night's on the mountain, as sleep's on the stream,
My heart is in darkness, my soul is a-dream.

Red dawn is at breaking and Sliabh-Mis is glad,
In smiles to the green fields and fallows of Braghad,
Carraig-bile is waking from night's dewy sleep,
And Cealla's young stream with my new pulses leap.

Down wild Sliabh-na-ngaoth the Lammas winds roar,
Their pealings re-echoed from rocky Pairc-Mor,
Gleann-airbh is troubled—my brain is afire,
For love unrequited and hindered desire.

Meek eve calms the rough brow of mighty Beann-uamhain,
And Dubh-ais for sorrow looks out at the moon,
As day sets on Sean-cill and Dun-mor macAirt,
The sweet light of memory is quencht in my heart.

As fleet as the changes on the mountain and vale,
So fleet are my moods and so many their tale.
I sigh with the shadow, I laugh with the shine,
And with joy in the hill's heart there's gladness in mine.

The blue hills of Antrim I see in my dreams,
The blue hills of Antrim, the glens and the streams,
In sunlight and shadow, in weal and in woe,
The sweet vision haunts me wherever I go.