Canyon Lake Gorge is a gorge around 1 mile (1.6 km) long, hundreds of yards (metres) wide, and up to 50 feet (15 m) or more deep, which was carved through limestone in 2002 when extensive flooding of the Guadalupe River led to a huge amount of water going over the spillway from the Canyon Lake, Texas, reservoir. The gorge provides a valuable exposure of rock strata as old as 100 million years showing fossils and a set of dinosaur tracks, and forms a new ecosystem for wildlife with carp and other creatures in a series of pools fed by springs and waterfalls. The Gorge Preservation Society formed as a local citizen's group is developing long-term plans for the Gorge in partnership with the Guadalupe-Blanco River Authority and the U.S. Army Corps of Engineers. Public access to the gorge is restricted to guided tours along a designated route for a demanding hike lasting about three hours. Availability of tours is limited, no pets are allowed and no rock or fossil collecting is allowed.