Donald Trump Jr. will travel to Boulder on Monday to speak with supporters of his father’s presidential bid and campaign volunteers, the Donald Trump campaign announced Sunday morning.

Trump’s son is scheduled to appear at 4:30 p.m. Monday at The Sink, 165 13th St., following a morning campaign appearance in Centennial, according to an email from the campaign.

But Laura Thoman, a manager at The Sink, said Sunday afternoon that no one from the Trump campaign had contacted the restaurant.

“We’ve had a lot of famous people here, but we usually get some advanced warning,” she said.

No other details of the Boulder event have been released.

Contacted later Sunday afternoon, Lydia B. Blaha, the Trump campaign’s Colorado communications director, said the event is expected to take place inside The Sink.

The Sink, a decades-long fixture of Boulder’s University Hill, has a small but notable place in the city’s history of presidential politics.

In April 2012, after delivering a policy speech at the University of Colorado, President Barack Obama’s motorcade stopped at The Sink, where Obama met diners and spoke to people out on the sidewalk.

While outside the restaurant, someone famously spilled a purple yogurt snack on the president’s trousers, and Obama also was introduced to a smartphone app by a Boulder company called Sphero that could control a moving ball — the future basis of the wildly popular “Star Wars” BB-8 toys.