There’s no turning back. Freshman Sami Weyhrich tries to hide her fear by focusing on details that swell in the woods. The blanket of leaves below her feet. The glitter of light that gently pokes through the patchy, green clouds surrounding her. The feeling of bliss in her chest that the birds evoke through their songs. But with a misplaced step, a mixture of terror and adrenaline shoots through her entire body. She clings onto the rope so tight that her fingers cramp. Sami laughs, in confusion of anxiety and excitement. She knows she won’t fall to the ground; the Go Ape! instructor has already given her a 30-minute training session on how to properly use the equipment that connects her to the zip line.

More than 2,600 feet of zip lines and obstacles weave through the woods of Creve Coeur Park, each obstacle raising in height as the course unfolds. The zip lines range from 13 feet to 400 feet and the participants reach speeds of around 30 mph, then slow to around 15 mph for a soft landing in a pile of mulch. Rope ladders, Tarzan swings, spider webs, suspended logs, and many more obstacles also make up the course–all of which are located up in the treetops. According to Sami, the course helped her overcome her anxiety when it came to heights. Sami’s sister, junior Allison Weyhrich, doesn’t share the fear of heights and enjoyed being in the treetops.

“My favorite part was the little obstacles before the actual zip line because they were challenging,” Weyhrich said. “I used to like ‘Survivor’ when I was a kid. I always wanted to be on ‘Survivor.’ It was kind of like that.”

Go Ape! opened in July 2013, taking about four weeks and $500,000 to build. The treetop adventure course will be open until December and will reopen in March when the weather gets warmer. Not only does Go Ape! offer another activity to do at Creve Coeur Park, but it also takes part in service projects such as park clean-ups and planting. Go Ape! also gives a portion of its proceeds to the park.

“We were looking around at a bunch of different parks in the St. Louis area and St. Louis County really wanted us here,” the site manager at Go Ape!, Anthony Giovino, said. “When they said ‘Yeah, we’d love to have a partnership with you guys,’ that made us want to work with them because they wanted to work with us, so this course was born. We bounced around a couple of parks and, in the end, this is the one that had a great location, had space to work, and we weren’t going to disturb a lot of other sections of the park here.”

Unlike many other zip line courses, Go Ape! allows participants to travel through the courses on their own without a guide. According to Giovino, the zip lines are supposed to serve as a rewarding end to the obstacles before them.

“Just come looking to have fun with a positive attitude and try to relax while you’re up there,” Giovino said.