Employment in the once-booming American mining sector continues to drop, according to the latest jobs data from the U.S. Department of Labor. November’s report, released Friday morning, shows 11,000 miners lost their jobs last month.

Since reaching a peak last December, mining jobs have declined by 123,000. That’s largely the result of struggles in the oil, gas and coal industries.

Low global crude prices have hampered employers in the oil and gas sector: With crude oil prices hovering near $40 a barrel -- down from about $70 last November -- domestic drillers have found it increasingly difficult to compete. Suppliers have struggled too. This week, global oil field services giant Schlumberger announced plans to slash an unspecified number of jobs, adding to the 20,000 layoffs worldwide this year.

The coal-mining sector has problems of its own. The widespread availability of cheap natural gas and increased federal regulation have cut profits across the industry. Since the start of 2014, some of the country’s biggest coal companies have gone bankrupt, including Alpha Natural Resources, Patriot Coal, Walter Energy and James River Coal.

Last month, the country’s largest underground coal company, Murray Energy, announced plans to close one of its mines in southern Illinois by the middle of 2016.

RTX1KAIK American roughnecks have seen better days. In this photo, a service truck drives past an oil well on the Fort Berthold Indian Reservation in North Dakota, Nov. 1, 2014. Photo: Reuters/Andrew Cullen