John Muir, perhaps the best friend the national parks ever had, died on Christmas Eve, 1914. Here are some numbers that tell the story of the National Historic Site created to preserve and interpret the place he called home for the last 24 years of his life.

Stories passed down about the harsh Continental Army encampment at Valley Forge during the winter of 1777-78 often note the brutally cold, snowy weather and the under-equipped and hungry troops. Should we be surprised that some of the soldiers were "fond of strong liquor"?

Can the grasslands in Yellowstone National Park support the park's bison herds? That's a question that researchers from Syracuse University will examine during a three-year study into bison grazing habits in the iconic park.