Huge boulders blocked the way in some places.

How they got into the valley is still a mystery, although possibly a huge boulder has blocked the entrance they once used.

A boulder had formed within it and was blocking the egress of a deep spring-fed river.

Sure enough, a sizeable boulder had blocked it, and all that showed through were a few small cracks of sunlight from outside.

On all sides boulders blocked her crippled view, but she was in no hurry to see more.

A huge gray boulder blocked all but a wedge of our view.

Huge boulders crashed down and blocked the road bed.

But he had not walked a dozen paces before he found that a giant boulder blocked his way.

Half an hour later, they came to a place where a fallen boulder blocked most of the path.

Two large boulders blocked his view, with only a narrow passageway between them.