Riding the range at the Ponderosa

We've recently been watching reruns of the old Bonanza TV series from the 1960s. The story concerns the Cartwright family, who supposedly lived in the 1860s on a huge ranch called the Ponderosa near Virginia City, Nevada. Many episodes refer to the awesome size of the Ponderosa, and finally I couldn't resist working out exactly how big the ranch really "was".  It helps that this map appears in the title sequence of every episode, as well as on the wall behind Ben Cartwright's desk (click the map to see it in a separate window):

By comparing that map to the real one below taken from Google Maps, I had a scale by which to estimate the size of the Ponderosa. First I had to rotate the real map to match the odd angle of the one above. I also had to work around a few liberties the old map had taken with the positions of certain landmarks, such as Washoe Lake:

Google's scale tells me that Lake Tahoe is about 20 miles long. Using that as a ruler, I estimate the area of the Ponderosa as 150 square miles, which is 20% larger than the entire city of Surrey, BC where I live.

So yes, the Ponderosa was really big, but not unimaginably so. There was also plenty of room for the Ponderosa to contain mountains, forests, deserts, green valleys and small lakes the show portrays. The island of St. Croix in the US Virgin Islands, which is only about half the size of the Ponderosa, has all of those, including every kind of environment from tropical rain forest at the west end of the island to tumbleweed desert at the east end, as well as two major factories and at least three towns.

But knowing the true size of the Ponderosa does cast some doubt on the speed at which people could apparently travel between Virginia City and the Ponderosa on horseback!