The number of active oil and natural gas rigs in the United States fell for the first time in a month – declining by 6 to 1,811 for the week ending November 30, 2012 – down 0.3% from last week and 9.1% from a year ago.

The highest weekly rig count in the United States since 1940 was recorded on December 28, 1981, at 4,530; the lowest was recorded on April 23, 1999, at 488.

The number of rigs in Canada rose for the third straight week – up 3.1% to 399 from 387 last week, but was 17.6% below the year-ago level.

The highest rig count for Canada was 727 on February 3, 2006; the lowest was 29, recorded on April 24, 1992.

Source: Baker Hughes Inc.