Even fish ladders prove impassable to some species that migrate up rivers, such as short-nosed sturgeon, he said.

The Charlestown Neck proved almost impassable.

On inspection, the edges of that raw wound proved impassable, even for an E-suit.

Generally, athletes bridge that funding gap with personal finances; for financially disadvantaged athletes, that gap may prove impassable.

Unfortunately, bad roads proved impassable to his heavy siege guns.

Sump 12 has so far proved impassable.

The wreckage debris might very well prove impassable.

There now loomed aloft a great beetling mass which hampered the upward view, and Carter was for a moment shaken with doubt lest it prove impassable.

This was in part due to the amount of railroad property traversing the area which proved impassable for larger apparatus.

After a swim of seven miles, carried out without casualties, the terrain proved impassable and only three tanks were able to advance with the infantry.