Fortynine Palms Oasis Trail - Twentynine Palms

Location: From Highway 62 heading west from downtown Twentynine Palms, take Canyon Drive south 1.7 miles to end of the road, Fortynine Palms Parking Area
Why Go There? Part of Joshua Tree National Park, accessible without going through the closest park entrance gate (ie. no fee), the short three mile roundtrip hike to the stunning fan palms oasis offers 300 feet elevation gain, loss in both directions, and great views down into the valley. Not recommended during heat, as trail is very exposed; popular, expect to share trail.
More Information: Fortynine Palms Oasis

Moorten Botanical Garden and Cactarium - Palm Springs

Fall, Spring, Winter 10:00am-4:00pm (closed Wednesday) 
June 21-September 21 9:00am-1:00pm (closed Wednesday)
Location: 1701 South Palm Canyon Drive
Why Go There? More of a short stroll, family-owned one acre collection of 3000+ succulents, cacti, small entrance fee, self-guided map; tours offered.
More Information: Moorten Botanical Garden

Additional Resources

National Parks Service - Joshua tree National Park
Hiking trails

Aerial Tramway - Palm Springs
Mt. San Jacinto State Park tram leads to miles of trails, spectacular views, escape from valley heat during summer; often snow covered in winter

Hiking Trails - Palm Springs Area
Useful hiking information, descriptions

Walk of the Inns - Palm Springs
Annual December evening self-guided "walk of the inns" tour

Park Trails - Rancho Mirage
Jack Rabbit, Roadrunner Trails are popular, low elevation gain, short trails