In 1911, amateur ornithologist Frank Willard marveled at the huge mesquite trees dominating the Santa Cruz River banks near what is now San Xavier Road south of Tucson:

“The mesquite trees are wonders of their kind. … There were some whose trunks at the base scaled over four feet in diameter. The large bases branched a few feet into several limbs 15 or 18 inches in diameter,” Willard was quoted in the book, “Requiem for the Santa Cruz.”

For many decades, this mesquite bosque, covering seven square miles, was a mecca for bird lovers and scientists. From 60 to more than 70 bird species were known to have bred there at various times from the turn of the 20th century until the 1940s, and well over 100 species total lived there. The bosque helped make the Tucson area one of the ornithological capitals of the Southwest.

But the introduction of large-scale groundwater pumping in the 1920s and onward, coupled with widespread tree-cutting for firewood and power supplies, destroyed the bosque by the 1960s, said the Santa Cruz book, written by four longtime Tucson-area scientists.

Now, with perennial water flowing once again on the Santa Cruz at San Xavier Road, and small cottonwood shoots starting to reappear, will this bosque come back?