Wikipedia: The Rincon Mountain District is located at the eastern edge of Tucson, Arizona; the east side of the park was the original National Monument. What is unique about this park is that it starts off in the Sonoran Desert and gradually gives way to a montane coniferous forest of the Rincon Mountains. The highest peak in this range is Mica Mountain, at an elevation of 8,666 feet (2,641 m). While this side of the park has fewer Saguaros than its counterpart they remain larger in size, due to higher amounts of rainfall and run off from the Rincon Mountains.
Saguaro National Park, Rincon Mountain District
The key feature of this district is its 8.3-mile (13.4 km) loop, which connects its two picnic areas and central trails. Recently after a lengthy road improvement project, and refurbishment of the Visitor Center, the Rincon District is fully open once more.