President Trump insists he's on a "working vacation," but that hasn't stopped the Secret Service from spending $13,500 on golf cart rentals ahead of this go-round in Bedminster, N.J.

A purchase order, pulled by progressive super PAC American Bridge and reviewed by USA TODAY, showed the agency signed the golf cart rental contract last week, the day before the president left for his 17-day vacation up at Trump National Golf Club.

The New York vendor providing the golf carts to the Secret Service has daily, weekly and month rental rates. Weekly rates range from $500 to $900 a cart, depending on the model and monthly rates range from $750 to $1,200 a cart.

The agency also signed two rental contracts with the same company in June, each worth $5,400.

Additionally, the Secret Service spent $35,185 on rental contracts earlier this year down in Florida, when Trump was regularly visiting Mar-a-Lago before it closed for the season.

That brings the grand total spent on golf cart rentals so far this year to $59,585.

American Bridge was critical of the expenses.

"Trump's vacations are costing Americans bigly — from the thousands of dollars the Secret Service is spending on golf carts to trail Trump on the course this week to the millions of taxpayer dollars already spent on his constant vacationing," Brad Bainum of American Bridge said. "If all Trump wants to do is play golf and watch TV, he should do us all a favor and retire."

The costs are, of course, a small part of the mounting expenses the Secret Service has spent to protect Trump since he took office. Back in March, the agency requested an additional $60 million to cover the costs. Last week, lease negotiations between the General Services Administration and the Trump Organization reportedly fell apart, resulting in the Secret Service vacating its command center in Trump Tower.