YA novel, time travel through standing stones, Druids

Young girl, away for summer, wanders through standing stones and travels back in time. There were Druid priests and sacrifice?
Book cover had what looked like a jean pocket around the border,
Not The Outlander by Diana Gabaldon.
I read it in late '80's or early '90's.
Thanks for any help!

An Acceptable Time?

Wikipedia has a detailed summary page:

http://en.wikipedia.org/wiki/An_Acceptable_Time

The Druid's Tune or The Singing Stone by OR Melling, maybe?

Some of the details don't match, but In the Circle of Time has a girl and a boy who travel into the future. However, the future is a bit primative. I don't remember any druid priests, but it's been a long time since I've read it.

I found it
Been looking forever. Your description of it as denim is bang on. I think of it that way too.

Has to be this one
HAS TO BE

I found it and am riding on a high
I posted elsewhere and let that person know as well

https://www.goodreads.com/book/show/675678.The_Stone_in_the_Meadow

If it is, Hope you rest easier! I know I will!

Nice work!

Touchstone: The Stone in the Meadow by Karleen Bradford. (Wrong cover)