DIRECTIONS:  From I-25 exit at Larkspur (exit 173).  Pass through the town of Larkspur and turn right onto Perry Park Avenue.  After about 3 miles turn left onto Highway 105.  Continue for .6 mile abd turn right into Sandstone Ranch Open Space. 
Sandstone Ranch is the newest addition to the Douglas County Open Space system and the Gamble Oak Loop is great introduction to the park.  This is a few easy, short trail but it gives you a taste of what Sandstone Ranch is all about.  The trail is good for kids and great for a short easy hike year-round.

From the very large parking area enter the trail system at the pavilion and turn left.  At the four way intersection follow the signs and stay straight for the Gamble Oak Loop.  Turning left or right takes you to the 3 1/2 mile Sandstone Meadow Loop.  Before too long you'll reach the start of the loop.

If you hike the loop counter-clockwise you'll bear right and enter a Gamble Oak forest. The red dirt trail undulates with the hilly landscape cutting through the oaks and providing near constant views of the foothills.  Before you know it you'll have returned to the start of the loop.  If I have one complaint its that this trail seems just a bit too short, even my 3 year old wanted to hike more...

The Gamble Oak Loop is beautiful and a great hike but I would recommend combining it with another trail for a longer hike.  There is a connector trail, half way through the loop, that connects to the Sandstone Meadow Loop allowing you to create a longer loop.