"While the long-term effects are uncertain, researchers say the construction of the wall has cut through habitats already threatened by the changing climate."

"Along the southernmost edge of Arizona, where the San Pedro River once flowed freely over the border from its headwaters in Mexico, a 30-foot steel wall slices across the channel. The barrier resembles a fortress, with massive floodgates, a concrete bridge and light poles that tower over the riverbed.

Before the Trump administration broke ground on the new wall, the river and the shady forest along it had cut through the only opening in a stretch of 40 miles of fence. Now, environmentalists and others who live near the border fear for the animals that will hit an impenetrable barrier on their journeys north and south and they wonder what will happen the next time dangerous floods rush through.

The river, which provides habitat for a diverse array of wildlife, has emerged as a symbol of the ecological damage that conservationists say was inflicted when new segments of wall severed wilderness areas across the borderlands. "

Erin Stone, Anton L. Delgado, and Ian James report for the Arizona Republic April 15, 2021. [2]