Bones of the Hills has 416 pages.
Clouded Hills has 381 pages.
The Seven Hills has 368 pages.
Hills End has 174 pages.
The Horror from the Hills has 110 pages.
Escape to the Hills has 247 pages.
Bicycle Hills has 204 pages.
The Far Hills has 238 pages.
The Hollow Hills is by Mary Stewart. The paperback is 475 pages. The hardcover book is 501 pages.
The Dark Hills Divide by Patrick Carman has 256 pages.
The Farming of Bones has 312 pages.
The Lair of Bones has 464 pages.
The Road of Bones has 224 pages.