There is a gravel trail from Greenland through Palmer Lake, the Air Force Academy, Colorado Springs and Fountain. The New Santa Fe Trail.
There is a dirt road connecting a paved road from Larkspur (which goes to Monument) to the Greenland Trailhead.
There are a variety of ways to get to Larkspur.
There are a whole bunch of Denver Metro Area riders here, we have our own "thread".
http://www.bikeforums.net/showthread.php?t=80754
If you are planning on going to the Santa Fe Century, check this out:
http://www.bikeforums.net/showthread.php?t=94891
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