3 Colorado Springs-area Halloween/fall festival events × Close By Carlotta Olson Updated: November 1, 2017 at 10:01 am • Published: October 31, 2017 • 0 Preparations were being made for the opening day of the annual Boo at the Zoo at the Cheyenne Mountain Zoo on Thursday, October 18, 2012. Zoo employees Erica Meyer and Nadia Stimack (left to right) transform the beaver grotto into a Pirate's Cove to get ready for Friday's opening night. This year the Halloween event will have extended hours, from 4-9 p.m. Boo at the Zoo will run from Friday through Sunday for the next two weekends. The beavers of the zoo will not be in the area with the pirates.(The Gazette/Jerilee Bennett) Through Nov. 4: Hellscream Haunted House — 3021 N. Hancock Ave., $20 and up. Advance tickets available online. Through Nov. 4: Sinister Haunted House — 3910 Palmer Park Blvd., $20 and up. Advance tickets available online. Through Nov. 11: 13th Floor Denver — 3400 E. 52nd Ave., Denver, $19.99 and up. Advance tickets available online.