Finger Rock, is shorter (about 10 miles) but steep, very rugged and a bit scary for those with vertigo. It is like a huge stairmaster. It has great views of the canyon and Tucson from the upper canyon and very good views of Oro Valley and the high northern Catalinas from the Mt Kimball peak. The top section has a lot of burn damage from the Bighorn Fire.
Pima Canyon, is the trail to take to get the best full-canyon view, as is shown on this website's home page. The trail is long to fairly long (about 13.5 miles to the canyon top, where the home page picture was taken, and about 18 miles if you carry on to the top of Mount Kimball). It also connects to Finger Rock at Mount Kimball. The trail has lots of vertical (3,500 to over 4,000 feet) contributing to making it a good workout. It can be busy in the lower section, but I've rarely seen more than a few hikers above the pools about 40% of the way up. The top of the trail is very eroded and difficult to follow and there is a fair bit of fire damage near the top and some from about 2 miles in. There are lots of varied views and vegetation types ranging from desert to chaparral to forests.
Ventana Canyon, has spectacular lower canyon views and it is close to a major resort of the same name. Ventana is a fairly long trail (about 11-12 miles to the top of the canyon, with much more possible along the top trails). The trail connects to the Esperero trail if you want a long loop trail (although they do not connect at the bottom). This trail is a bit easier, relatively well marked and does not have difficult/scary sections. Still, it is a real workout with good vertical and length. It can be a busy in the lower section due to the close proximity to the Ventana Canyon resort and popularity as an excursion option from some Tucson-area luxury resorts.
Esperero Canyon, is a long trail with considerable vertical (around 15 miles and about 4,000 feet vertical) departing from the popular Sabino Canyon Reacreational Area and traversing the western and northern parts of the Sabino area. The front side has beautiful desert mountain and canyon hiking leading to the steep "Cardiac Gap" wall about half way up. The view from the top of the Cardiac Gap zig zag climb is very nice. Few hikers venture beyond Cardiac Gap, which marks the start of the high-country plateau. The first section beyond Cardiac Gap is a bit of a moonscape due to fire damage, but you descend into a beautiful forested meadow that follows Esperero creek called Geronimo Meadows after about 45 minutes of hiking. There are some spectacular mountain vistas along Geronimo Meadows. The trail becomes considerably more steep after Geronimo Meadows and leads to the very high country trails along the ridge at the top of the front side of the Catalinas. The views are spectacular from the top. The hiking is strenuous in places and the length and vertical make it a great workout, but there are no scary parts on the trail.
The Sabino Loop, also departs from the Sabino Canyon Reacreational Area, but follows Sabino's southern, eastern and central canyons. This trail loop is very long, but has less vertical than the other Catalina and Rincons trails described in this website (over 17 miles long, about 2,900 feet vertical). The Loop is comprised of Bear Canyon Trail, East Fork Trail (part of the state-long Arizona Trail), Sabino Canyon Trail and Phoneline Trail. I always start on the southern Bear Canyon Trail and return the northern Phoneline Trail as you can catch a tram down to the end of the trail from Phoneline if you are tired by that point. Bear Canyon has beautiful views of a waterfall called Seven Falls and spectacular canyon views from its mid-point. Bear Canyon can be very busy up to Seven Falls, but is generally empty after that point. East Fork Trail is back-country territory, which feels very remote. It has nice forest sections and great views of the very high country peaks. Sabino Canyon Trail has spectacular views of the massive rock canyon sides of Sabino Creek. Phoneline provides beautiful views down the expansive lower section of Sabino Canyon and impressive ridge line and Saguaro forest scenery.
Romero Canyon, departs from the Catalina State Park on the east side of Oro Valley, Tucson's northwestern exurb. It is another long trail with moderate vertical (about 14 miles and 3,300 feet vertical). The trail traverses the center of the Catalinas along the roughly east-west Romero Canyon. This canyon separates the southern Catalinas that face Tucson from the very high northern Catalinas that peak at the range high-point, Mount Lemmon. There are two quite vertical sections to the trail, one on the range facing Oro Valley and the other in the mile or so leading to Romero Pass at the top. Neither is scary, but both are a workout and the Pass section can be difficult to follow and quite eroded near the very top. The middle section of the trail is a long beautiful plateau. The trail provides stunning canyon and peak views in the front side range, some nice waterscapes, chaparral and forest views in the middle and beautiful high mountain vistas from Romero Pass. Romero Pass connects with the Mount Lemmon trails and the West Fork and Cathedral Rock Trails of the Sabino Recreational Area. In theory, you could use Romero to hike up Mount Lemmon or down to the bottom of the Sabino Loop from the Catalina State Park in a single day, but this would require great fitness, a lot of daylight hours and considerable water and food. Maybe someday I will try. Note that this trail has been closed due to fire damage since June 2020, with a posted opening expected for October 2021. Update: The trail is now open to Romero Pools, but remains closed beyond that point (as of December 2021).
Rincons - Douglas Springs Trail to Mica Mountain, departs from the far eastern end of one of Tucson's main streets, Speedway Boulevard. The trail system follows Douglas Springs Trail to Cow Head Pass and then Cow Head Pass Trail to Mica Mountain. This trail is long to extremely long with significant to extreme vertical, depending on how much of the trail you do. It ranges from 16.6 miles and 3,750 feet vertical (Douglas Springs Trail to Cow Head Pass) to 25.4 miles and 6,437 feet vertical if you go all the way to the top of Mica Mountain. I generally hike about 18 miles and 4,000+ feet vertical and I haven't gotten much beyond 20 miles. The trail is fairly easy, but the length and vertical make it exhausting. The bottom section is very lengthy low desert and chaparral terrain - nice but very long to get to the more beautiful forested sections in the upper parts of the trail. This trail can also get a fair bit of snow in the upper sections - beautiful, but difficult to hike when it gets to two feet! The Ponderosa pines in the higher elevations can be towering, quite a difference from the Saguaros and other desert plants at the start of the trail.
King Canyon is very close to the Arizona-Sonora Desert Museum, a world-class zoo/botanical garden just west of the Tucson Mountains. The trail is a loop up the west side of the Tucson Mountains. It provides beautiful views of an immense saguaro forest and panoramic views of Tucson. It goes to the top of Wasson Peak, the highest peak in the Tucson Mountains (4,688 feet). I would rate the trail as a moderate trail - not hard but long enough (7.9 miles) and with some vertical (1,863 feet) to make it a good workout. There are beautiful wildflowers in the spring (March/April).
Hugh Norris is another trail on the west side of the Tucson Mountains, very close to the King Canyon loop trail (they overlap for some distance). Hugh Norris is an out-and-back trail to the top of Wasson Peak, the highest peak in the Tucson Mountains (4,688 feet). I would rate the trail as a moderate trail, although slightly harder than King Canyon due to more vertical (2,398 feet) and distance (8.9 miles). As with King Canyon, it provides great views of the immense saguaro forest, panoramic views of Tucson and great wildflowers in the spring (March/April).