Crossword puzzle clue "almost vertical like many canyon walls"

Almost vertical, like many canyon walls

Add vertical line 13 (word 3) and vertical line 3 (word 1) together and enter the answer to the resulting clue on this line

Add vertical line 9 (word 2) and vertical line 7 (word 2) and enter the answer to the resulting clue on this line

Add vertical line 1 (word 1) and vertical line 15 (word 3) and enter the answer to the resulting clue on this line

Add vertical line 15 (word 1) and vertical line 1 (word 3) and enter the answer to the resulting clue on this line

Actress Larson who portrayed Jeannette Walls in "The Glass Castle," to the delight of Walls herself

Steep canyon walls

Bouncing off the Grand Canyon walls