Trump has expressed doubts about the science of climate change and has blamed former President Barack Obama’s efforts to cut carbon emissions.
Police declared the scene an unlawful assembly, threatened to deploy tear gas and arrested at least eight people.
Trump is continuing to hear from his advisors on the pros and cons of the US remaining in the Paris Climate Change Agreement.
Trump advisors have taken different sides on whether to stay or exit the pact, but major US companies are petitioning to remain to protect competitiveness.
Conservation groups and native American tribal representatives slammed the looming order on monuments, suggesting it would be fought in court.
The opposition to the controversial Keystone XL pipeline continues as farmers and landowners move to derail the project, reopened after Trump’s approval.
The wide-ranging order is the boldest yet in Trump’s push to cut environmental regulation to revive the oil and gas drilling and coal mining industries.
The climate change page contains links to scientific global warming research, as well as detailed data on emissions.
The Paris Agreement seeks to wean the world economy off fossil fuels, limiting the rise in average world temperatures to well below 2 degrees Celsius.