(Finkelstein 2005) harv error: no target: CITEREFFinkelstein2005 (help)[4] The descendants of the Cree and Chipewyan First Nations continue to carry on traditional fishing, hunting and trapping activities."[5] In 1922, Wood Buffalo National Park was established to protect the remnant population of bison that escaped the slaughter in the late 19th century.(Finkelstein 2005) harv error: no target: CITEREFFinkelstein2005 (help)[4] It became the world's largest herd of free roaming wood bison, currently estimated at more than 5,000.Bennett hydroelectric dam at the headwaters of the Peace River", the Peace–Athabasca delta experienced a "prolonged dry period" that turned some basins from aquatic into terrestrial ecosystems.(EC 2005)[6] In 1974, a major flood occurred in the region and, when the spring water receded, the delta experienced a second prolonged dry period.PADEMP chair, Stuart Macmillan representing Parks Canada, observed that, "I think everybody realizes if we don’t do this now, we’re in danger of losing something very special in the delta.According to Chris Heron, the NWT Metis Nation representative of the PADEMP, the use of traditional knowledge to determine the ecological health of the Peace–Athabasca Delta and their findings will be investigated using western science.Bennett Dam was constructed on the Peace River in northern British Columbia by BC Hydro, a major hydropower utility.[citation needed] An ongoing lawsuit between BC Hydro and local First Nations bands relates to the effects of Bennett Dam on delta water levels and associated traditional lifestyles.