This was published by Gale Huntington in Sam Henry's Songs of the People as collected by Sam Henry in 1937. A number of covers have been made. It's similar to other versions of "Sweet Bann Water" such as Len Graham's version (source: Joe Holmes?). There are several texts online with no attribution. They are missing the additional Drowsy Sleeper stanzas and are versions related to The Grey Cock (The Ghostly Lover/The Lover's Ghost):
Sweet Bann Water
I must away, I'll no longer tarry, The Sweet Bann Water I mean to cross, And over the mountains I'll go with pleasure, To spend a night with my own sweet lass.
Though the night be as dark as a dungeon, Not a star to be seen above, I will be guided without a stumble Into the arms of my own true love.
When he came to his true love's window, He knelt gently upon a stone, And through the window he whispered slowly, My darling dear, do you lie alone?
She raised her head from her downy pillow, And slowly raised her milk-white breast, Saying, Who is this at my bedroom window, Disturbing me at my night's rest ?
Arise, arise, it's your true lover, Arise, my love, and let me in, For I am weary of my long journey And I am wet, love, unto the skin.
It's up she got, with greatest pleasure, For to let her true love in. They both embraced and they kissed each other, And till morning they lay as one.
The cocks were crowing, the birds were whistling, The night drew on to the break of day. Remember, lass, I'm a ploughboy laddie, And the farmer I must obey.
Now, my love, I must go and leave you, To climb the hills, they lie high above, But I will climb with greatest pleasure Since I've been lying with my love. [source???]
Since the Sam Henry version has "high hills and lofty mountains" or a line resembling that I was wondering about broadside "The Wandering Maiden" that you mentioned. Is it in the Bodleian?
Also if anyone has lyrics to Sarah Ogan Gunning's Silver Dagger or knows where a recording is online- I'd appreciate it.