Crocodile Lake National Wildlife Refuge (CLWR) and Dagny Johnson Key Largo Hammock Botanical State Park (KLH) are separated by the County Road 905 right-of-way for approximately 10 miles. On April 13, 2007, two researchers were studying North Key Largo's population of Key Largo woodrats, one of two federally endangered mammals found only in North Key Largo (the other being the Key Largo cotton mouse). Graduate student / biologist Joanne Potts and her assistant, Wildlife Refuge volunteer Clay DeGayner, were working in KLH and tracking a telemetry signal transmitted by one of several radio collars they had placed on a small number of woodrats. The signal led them to a python weighing 12-pounds and measuring approximately seven feet in length, the radio signal was coming from inside the python. A post-mortem examination revealed that the snake had very recently captured and eaten, not only the collared woodrat, but also a second (uncollared) woodrat. The python also turned out to be the first vouchered (verified by a specimen or photograph) occurrence of its species found wild in the Florida Keys. However, over the following year, another half-dozen pythons were found after they were killed by traffic on roads in the same area.