Minimum security facilities generally offer more freedom of movement than higher security levels, and Rapid City's minimum unit is consistent with that.
Inmates have access to a track for walking and running, weight equipment, and organized sports and recreational activities. The atmosphere is noticeably more relaxed than what you find at medium or maximum security facilities. There is room to move, time outside, and structured programming that keeps people engaged and active.
The reason minimum security works the way it does comes down to incentives. Inmates at this level typically have short sentences and are close to release. They have everything to lose by acting out and very little to gain. Taking someone's good time for a rule violation at minimum security means they finish their sentence in a much stricter environment, and most people in that position are not willing to make that trade.
That dynamic tends to produce a calmer population and a more manageable day to day environment for everyone inside. Inmates who stay out of trouble, participate in programming, and use the recreational outlets available to them do significantly easier time and protect their release date in the process.
For someone heading into a minimum security placement, taking full advantage of the track and physical activity is one of the best things they can do. Exercise is one of the most effective tools available for managing stress and making the time move faster.