Fossil Trail at LISDOLA Traditional Cache

LISDOLA is the Lewisville Independent School District Outdoor Learning Area.  It is land leased by LISD from the USACE and is used by LISD for their outdoor programs.  Total acreage of this area is over 2200 acres below the Lewisville Lake dam on the Elm Fork of the Trinity River. 

The Fossil Trail heads east from the classrooms at the main center off Fish Hatchery Road just north of SH121.  There is a map at the trailhead.  The Fossil Trail crosses McWhorter Creek, which is also the spillway for the dam.   Several types of fossils can be found at the terminus of the trail (see below for coordinates to general area for fossils).  The most abundant fossils I found in this area were ammonites (nautilus-like sea creatures), pelecypods (clams), and crustaceans (crabs and/or lobsters).  I also found filled burrows.  These burrows were created by pelecypods in that they used an appendage to anchor themselves to the seafloor to remain in place.  These burrows filled with mud and were later lithified.  They then weathered out in basically the same shape as the original burrows.  Go here for more info on the fossils-

 http://www.cretaceousfossils.com/invertebrates/main_page.htm

The fossils found here are in pieces.  I found very few fossils larger than fist-sized, and that was mostly ammonite fragments.  At the coordinates below, I left several ammonite fragments.  The host rock from which the fossils are coming from is a red shale.  The red color is coming from hematite, an iron oxide mineral.  This red shale overlays a dark gray shale which is the Eagle Ford Shale.  Sharks teeth and ray crushers have been found in this area.  Fossils can be found in approximately a 500 foot radius, maybe more.  Look around.  Check out the outcrops along the sides of the spillway and along McWhorter Creek.  I spent about 1/2 hour looking and came up with a few fragments.  

Several things I have noted is that on some of the ammonite pieces, the "mother-of-pearl" coating can still be observed.  This coating was part of the inside of the camera (Latin for "room"), which are the individual growth chambers of a growing ammonite.  Also, suture lines, or growth boundaries between cameras are observable.  The suture lines are used to identify the many species of ammonites and can be very complex and convoluted.  

The clams were basically found intact.  The crab and lobsters carapaces were only found in small pieces embedded in the red shale.  I've included some photographs of what to look for.  I also placed some pieces that I found in the cache pod.  If you find something unusual, please let me or Steve Spurger, the LISDOLA supervisor, know.  Take a picture and post it on the cache site.

Oh, by the way, the cache is a 50 cal ammo box painted dark brown.  You may want to find the cache first then come back to the fossil area.  Included in the cache originally were a disposable camera, a Golden Pecan, a Go Fish deck, some flower seeds, two travel bugs, and some other stuff I can't remember.  I did throw in a piece of coquina.  Coquina is a rock made up of mostly shells held together with limestone cement; this piece is not from this area and I don't remember where I found it.  The ammo box  is not well hidden.  If you would like to hide it better than you found it, please feel free.  Just send me the new coordinates if you decide to move it.  Also, if you want to put a sample of what you found in the ammo box, I included a ziplock bag to keep the fossils in to keep the ammo box from getting too dirty.

Caveats:  TICKS!!  I pulled two off of me when I got home.  These weren't small ones either.  Take precautions by wearing tight fitting clothing and using a repellant.  WEBWORMS:   this is the year for webworms.  I've heard a lot of people talking about them.  At one point along the trail they had the area almost blocked off.  MUD:  I found the best place for crossing McWhorter creek at the coordinates posted below. Note: if you follow the trail to its end, you will have to cross McWhorter Creek twice. The first crossing is obvious with planks of wood in place. The second crossing at the posted coordinates will be done heading south and this is not obvious. There is an alternative (which several have already taken) to taking the trail, but it takes you through waist high brush. Whatever works for you.  The surface near the creek may look dry, but when you step on it, one's foot may sink almost 1/2 a foot down.  The area has had some time to dry out.  Any rain will make this a mess, so you may want to wait several days after a good rain to let it dry out.  WATER:  bring water, lots of it (recommended 2 quarts/person - more if it's hot).  When you get down on the bottoms, it can be hot, dry, and windless.  Round trip is about 2.5 miles.  The difficulty is due mainly to the hike in and out, some moderate elevation changes, and lack of trail near the cache.  BARBED WIRE:  there is some old barbed wire near the cache.  I was able to navigate around it, but did get hung up on it once.  PARKING:  if you do this during a weekday when the gate is open, and you happen to stay longer than Steve Spurger, he will lock you in.  He usually leaves around 6pm, but check with him first before you leave your vehicle near the classroom buildings.  When in doubt, park on the south side of the gate and you'll be guaranteed a ride home.  NIGHT CACHING:  tempting.  There is a lot of critter activity out here at night.  Might be cool.

OK, enough with the caveats.  Be safe, be prepared, and have FUN!  For those of you who've been to LISDOLA before, you know what awaits you.  For those of you who haven't been, take the time to visit.

Parking:  N 33 ° 03.032 W 096 °56.185

Creek Crossing:  N 33 ° 03.283 W 096 ° 55.573

Fossils:  N 33 °03.275 W 096 °55.539