The rally is scheduled to begin at 5 p.m. Thursday at the Broadmoor World Arena.
Trump will speak alongside Sen. Cory Gardner at the event, which is first come, first served.
According to KXRM, supporters came prepared Wednesday afternoon with sleeping bags, tents and space heaters.
For those planning to attend the rally, parking opens at 6 a.m. Thursday. Doors to the arena open at 1 p.m. at Gate B.
Once parking lots are filled, cars will be turned away, so carpooling is encouraged.
Trump’s visit comes as several Democratic candidates are also trying to drum up support in Colorado. Sen. Bernie Sanders spoke in Denver last Sunday. Sen. Amy Klobuchar will be speaking in Aurora on Thursday. Former Mayor Pete Buttigieg will speak in Aurora this Saturday.