Out of curiousity, why does making an area a national momument inspire local hatred?
Westerners don't like how the federal government owns so much land in their states, making decisions on local land use from 2000 miles away. Declaring an area a national monument puts development off limits. And development in the rural west often means mineral or timber extraction jobs for an area that has little else in the way of jobs. Putting federal land off limits to development hurts the economy, at least in the short run.
Of course, the people who work the lumber or minerals have usually been Democrats. But on the other side -- workers in the tourist trade tend to be Democrats, too.