The Santa Fe Trail is a paved pedestrian/cycling trail that connects Deep Ellum/Fair Park with the White Rock Lake trail and the currently unpaved Union Pacific Trail. The original south terminus is S Hill Street, just west of I-30. (An extension has been added that runs between Deep Ellum and Fair Park.) The north terminus is at W. Lawther Drive and Lakewood Blvd, on the western shore of White Rock Lake. The trail is 4.6 miles long, including the 0.6 mile Santa Fe-Pacific extension. See related web page for more information.
The White Rock Lake Park Loop Trail connects to the White Rock Creek Greenbelt Trail. It is now possible to bike from Fair Park to Valley View Park at 635 & Hillcrest Rd.

The Dallas Bike Trail Network (visit link)
This cache is placed approximately 2.95 miles from the south end of the trail. (On October 18, 2012, the precedent cache was renamed from 2.55 to 2.95 based on odometer readings taken on October 17.)
Coordinates averaged for 12 minutes to 4.1 ft accuracy with Garmin 60Cx under clear skies and some foliage.
See GC2KGHG for trailhead coordinates.
Congratulations to ??? for third to find