Border wall tests find heights — say, 30 feet — should keep out crossers. But it'll cost more to build and could endanger nearby wildlife, opponents say.
![Indo-China border at Nathula pass at a height of 14150 feet - Reviews, Photos - Nathula Pass - Tripadvisor Indo-China border at Nathula pass at a height of 14150 feet - Reviews, Photos - Nathula Pass - Tripadvisor](https://media-cdn.tripadvisor.com/media/photo-s/02/3c/94/7e/pass-of-listening-ears.jpg)
Indo-China border at Nathula pass at a height of 14150 feet - Reviews, Photos - Nathula Pass - Tripadvisor
![Donald Trump's Mexico border wall will be as high as 55 feet, according to Donald Trump - The Washington Post Donald Trump's Mexico border wall will be as high as 55 feet, according to Donald Trump - The Washington Post](http://www.washingtonpost.com/blogs/the-fix/files/2016/02/Wall_6_Debate.jpg)
Donald Trump's Mexico border wall will be as high as 55 feet, according to Donald Trump - The Washington Post
![Border Of Horses Arranged In Order Of Height Royalty Free SVG, Cliparts, Vectors, And Stock Illustration. Image 75166858. Border Of Horses Arranged In Order Of Height Royalty Free SVG, Cliparts, Vectors, And Stock Illustration. Image 75166858.](https://previews.123rf.com/images/ayutaka/ayutaka1703/ayutaka170300026/75166858-border-of-horses-arranged-in-order-of-height.jpg)