WASHINGTON — President Obama designated two new national monuments on Wednesday, protecting 1.35 million acres of federal land surrounding the Bears Ears Buttes in southeastern Utah and about 300,000 acres around Gold Butte in Nevada, northeast of Las Vegas.

The monuments are Mr. Obama’s latest effort to protect public lands and waters from development and to nail down as much of his environmental legacy as he can before Donald J. Trump assumes the presidency on Jan. 20.

But some local residents and elected Republicans have opposed the Obama administration’s extensive efforts to protect Western landscapes, calling them federal land grabs, and Utah officials voiced vehement opposition on Wednesday. The family of a Nevada rancher, Cliven Bundy, helped take over a national wildlife refuge this year in protest against such federal actions.

The new desert monuments, designated under the executive authority of the 1906 Antiquities Act, encompass Native American sites of sacred and archaeological importance, as well as wildlife habitats and hiking and hunting terrain.