This trail appears to have been officially abandoned, likely in part because the spring is almost never a source of useful water. It is still possible to follow the route it followed, however.
The Fossil Spring Trail is accessible via Fossil Saddle along the Snowshed Trail, a third of a mile east of the Herb Martyr Trail junction just below Pine Park. (31.84711, -109.23498) This saddle is marked by a large tree which has two bolts screwed into it, at one time holding a sign which has since rotted away. The junction is otherwise unmarked.
Dropping away from Fossil Saddle, the Fossil Spring Trail heads south down a slope through brush that's encroaching on the trail in places. A faint path is visible most of the time, and flagging tape may be visible along the route at times. After approximately 350 feet, the trail swings to the southeast to contour along the north side of the Fossil Creek drainage, at times dropping into the usually dry drainage bottom. There are traces of the trail resuming its passage on the north side of the creek but they fade quickly over the last few hundred feet. Fossil Spring itself is undeveloped and there is no trace of it at the location it appears on maps.
Old USGS maps show this trail continuing along Fossil Creek an additional 1.43 miles to connect with the South Fork Trail but the viability of this connection remains unverified at this time and may have never existed.
Last updated April 22, 2014.