The Jeep Safari is an annual event hosted by the Red Rock 4-Wheelers off-road club, where 4-wheelers come to challenge the rough terrain of the backcountry in the Moab, Utah area.
Groups usually meet up early in the day, at a certain location in the city.
First waivers are signed and collected, then the drivers are given instruction and told to comply with any and all Bureau of Land Management regulations (i.e. stay on the trail, avoid walking on protected soil, etc.).
Once a group arrives at a trail, they will partially deflate ("air down") their tires to get better traction on sand or slick rock.
When a group approaches a really difficult obstacle, a few will get out and act as a spotter to ensure everyone makes it up or down safely.