DENVER — More trees for shade and an extension of the city's urban tree canopy along Denver's iconic 16th Street Mall are being planted as part of the walking mall's decade-long revitalization project ...

In central Phoenix, rows of multidecadal Aleppo pines and evergreens form lush corridors along residential city streets. Their canopies expand over roadways and sidewalks, diverting the Phoenix sun, ...

Sixty miles east of Winslow, on the windswept plains of the Painted Desert, maroon-colored Triassic fossils recall a forest more than 200 million years old. Felled logs of the ancient conifer species ...