Guess the book (I can never play by the rules even when I try....)

Dorothy did this meme today & since I had just finished cataloging my newly acquired books into LibraryThing and they were sitting nearby the keyboard, I had to do this. And I hated the results on page 123, but here they are. But, you'll have to guess the poem rather than the book (at least without any hints, but I've got that challenge for you too further down the post).

1. Grab the nearest book.
2. Open the book to page 123.
3. Find the fifth sentence.
4. Post the text of the next 4 sentences on your blog along with these instructions.
5. Don't you dare dig for that "cool" or "intellectual" book in your closet! I know you were thinking about it! Just pick up whatever is closest.

Fluttering and dancing in the breeze.
Continuous as the stars that shine
And twinkle on the Milky Way,
They stretched in never-ending line

Yeah, pretty easy and you could probably google it if you didn't know. But since this could be in any one of several anthologies, your challenge is to figure out what book it is in. Here are your clues regarding the book this appeared in.

1. American female poet who often writes about nature and spirituality.
2. Book is on craft, is not strictly an anthology, and its title is derived from a famous line by Pope.
3. Percy Bysshe Shelley is one of her favorites.
4. She gave a lecture this evening in city where I live.
5. Neither of the other two volumes I bought have 123 pages, so I added page total of 2nd book to 3rd book to find the page (e.g., 123-109=page 14) to get this from one of her own poems:

I see it still;
and there was once, oh wonderful,
a new horse in the pasture,
a tall, slim being -- a neighbor was keeping her there --

Make your guesses Friday. I'll want to post my answer soon, as well as writing about the reading!