WASHINGTON — As the head of the federal agency controlling billions of acres of public lands and waters, Interior Secretary Ryan Zinke has spent the past year making bold policy proclamations to advance President Trump’s energy agenda: He would open coastal waters to drilling, shrink national monuments, lift Obama-era fossil fuel regulations and reduce wildlife protections.

But legal experts say many of the moves were made without fully considering the laws and procedures governing changes like these, making them vulnerable to legal challenges that could delay or block them. They say many of the proposals may follow the fate of other bold and hasty moves by the Trump administration, such as the attempts to limit travel from countries with sizable Muslim populations on security grounds.

“They’re acting in a hurry, appealing to the base, and trying to seem decisive,” said Patrick Parenteau, a professor of environmental law at Vermont Law School. But, he added: “They’re not following the prescribed steps of the law. They’re creating errors for themselves as they go, sowing the seeds for the legal attacks.”

It is not unusual for major policy changes to be hit by lawsuits from opponents. The Obama administration’s own environmental regulations were sometimes controversial because they relied on creative interpretations of decades-old laws to rein in smokestack pollution or stop oil, gas and coal exploration.