Protesters blocked an access road to Mount Rushmore Friday, hours before President Trump was set to give a speech to kick off Independence Day weekend.

According to the Associated Press, the protest group was mostly Native Americans protesting that South Dakota’s Black Hills were taken from the Lakota people against treaty agreements.

One group parked three vans across the road and took the tires from two of them to make it more difficult to remove them. Several demonstrators climbed on top of the vans chanting “Land back!” Police warned the protesters to disperse but didn’t take any immediate action against them.

The sheriff’s office said attendees had been told to arrive early so should have been past the roadblock. However, the Rapid City Journal reported that some motorists who had tickets for Friday evening’s fireworks show were unable to get through the protests and were standing by their cars watching the standoff.

The Journal also reported that law enforcement in riot gear as well as members of the National Guard had arrived on the scene and declared an unlawful assembly.

The news outlet reported that the lower bowl of the amptheater where Trump was scheduled to speak at approximately 8:50 p.m. local time was full, but there were many empty seats in the upper level.

President Trump has been outspoken against the recent protests happening nationwide, targeting historical monuments and statues demonstrators feel represent a pattern of systematic racism in the U.S.