The Southeast Missouri Lead District, commonly called the Lead Belt, is a lead mining district in the southeastern part of Missouri. Counties in the Lead Belt include Saint Francois, Crawford, Dent, Iron, Madison, Reynolds, and Washington. This mining district is the most important and critical lead producer in the United States.

The potential for lead mining in Southeast Missouri was first discovered and documented in 1700 by Father James Gravier. Philip Francois Renault of France led a large exploratory mission in 1719 and started mining operations in Old Mines and Mine La Motte in 1720, establishing the first lead mining subdistrict of Mine LaMotte-Fredericktown.

Between the 1750s and 1799, production of lead in the region decreased. In 1799, Moses Austin settled in Potosi, originally known as Mine a Breton, bringing new mining methods and practices that revitalized lead mining in the district. Austin was the first to sink deep mine shafts and start smelting operations, dramatically increasing lead production. Before this time, lead mines had been surface or near-surface mines of less than 10 feet in depth. In 1808, Moses Austin and Samuel Hammond established the city of Herculaneum as a shipping point closer to the mining region, replacing Ste. Genevieve as the main shipping point to and from the mining district on the Mississippi River.

The Old Lead Belt Subdistrict was established in 1864 with the opening of the Bonne Terre Mine by the St. Joseph Lead Company. Notable mines in the subdistrict region included the Bonne Terre Mine, and mines near Doe Run, Desloge, Flat River (Park Hills), and Leadwood. In 1972, the last Old Lead Belt mine at Flat River closed, ending 108 years of lead mining in the Old Lead Belt.

The area of mining has changed over the years. The Old Lead Belt is centered on Park Hills and Desloge, while the New Lead Belt or Viburnum Trend is near Viburnum. The Irish Wilderness in Ripley and Oregon Counties has significant lead ore; however, this is a protected wilderness area. Significant among Missouri's lead mining concerns in the district was the Desloge family and Desloge Consolidated Lead Company in Desloge, Missouri and Bonne Terre—having been active in lead trading, mining and smelting from 1823 in Potosi to 1929. Lead mining operations were consolidated under the control of St. Joe Lead.

In the late 1940s, reserves in the Old Lead Belt began to decline, spurring new mineral exploration in the Southeast Missouri region. In 1955, the St. Joseph Lead Company discovered a new orebody near Viburnum, Missouri, leading to the opening of the Viburnum No. 27 Mine in 1960. The St. Joseph Lead Company, Cominco, Kennecott Copper, Amax, Inc., and Asarco companies conducted exploration that led to the opening of 10 additional mines, establishing what is known today as the Viburnum Trend, also called the New Lead Belt.

The Viburnum Trend is the only subdistrict mined for lead in the Southeast Missouri Lead District in modern day. Six lead mines are currently operational in 2022: the Brushy Creek, Buick, Casteel, Fletcher, and Sweetwater mines.

Today, many of the mines and mills of the Old Lead Belt have been abandoned or repurposed. Bonne Terre has large subterranean mines, now used commercially for recreational tourism and scuba diving. The Missouri Mines State Historic Site occupies the retired Federal Mill No. 3 in Park Hills.

The formal geological name for the Lead Belt is the "Southeastern Missouri Mississippi Valley-type Mineral District". It contains the highest concentration of galena (lead(II) sulfide) in the world as well as significant economic quantities of zinc, copper and silver and currently mined sub-economic quantities of metals such as cadmium, nickel and cobalt. Most of the mined ore minerals are found as sulfides, with the primary ore minerals galena and sphalerite, with minor sulfides pyrite, chalcopyrite, bornite, enargite, millerite, and arsenopyrite. Gangue minerals associated with the economic minerals include marcasite, calcite, dolomite, and quartz.

Sulfide and carbonate mineral specimens are highly prized by gem and mineral collectors and are found in museums worldwide.

The ore minerals of the Old Lead Belt are hosted in the dolomite of the lower Bonneterre Formation, and can extend into the underlying Lamotte Sandstone and rarely into the overlying Davis Formation. In the Viburnum Trend, lead-zinc ore mineralization is hosted in the bacterial stromatolite reefs dolomites of the upper Bonneterre Formation, and most orebodies are concentrated in areas where the Lamotte Sandstone pinches out against Precambrian igneous knobs and ridges. The Upper Cambrian age Bonneterre Formation was deposited in a shallow sea around the Precambrian age St. Francois Mountains, which formed an island archipelago. Ore mineralization most likely occurred during the Permian, when low-temperature hydrothermal metal-rich brines migrated through the Ozarks during the Ouachita orogeny in the Late Paleozoic.

Ore mineralization in the Lead Belt occurred as part of the same mineralization event, however, the intensity of mineralization and depositional controls differ between the Viburnum Trend and Old Lead Belt. In the Old Lead Belt, galena is more fine-grained and disseminated into the host rock, and large, euhedral crystals are rare. Ore is mostly constrained to the lower 60 feet of the Bonneterre Formation, and preferentially follow the lateral sedimentary beds and features. In the Viburnum Trend, zinc and copper are found in higher concentrations, and galena was able to form larger, more euhedral crystals. Ore mineralization in this subdistrict is prominently emplaced along collapse breccias, and not as influenced by lateral sedimentary features as in the Old Lead Belt. Ore in the Viburnum Trend can be found throughout the entire vertical extent of the Bonneterre Formation, but is mostly constrained to the upper 75 feet.

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  Cubic galena (lead ore) from the Sweetwater Mine of the Viburnum Trend (Reynolds County, Missouri).
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  Sphalerite, galena, and marcasite from the Viburnum Trend District (Reynolds County, Missouri).
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  Calcite and chalcopyrite specimen from the Brushy Creek Mine of the Viburnum Trend District (Reynolds County, Missouri).

The Lead Belt produces about 70% of the US primary supply of lead, and significant amounts of the nation's zinc. In the year 2000, Missouri produced 313,105 tons, with an estimated value of $128,838,880, according to Missouri DNR Data. About 84% of the lead is used for lead–acid batteries, and a secondary smelter in Boss, Missouri recycles lead–acid batteries. Another major consumer of Missouri lead is Winchester Ammunition, located in East Alton, Illinois.

From 1720 to its closure in 1959, the Mine La Motte-Fredericktown Subdistrict produced over 325,000 tons of lead. From 1864 to 1972, over 8.5 million tons of lead was produced from the Old Lead Belt Subdistrict. The Viburnum Trend is the only subdistrict still in production, and is primarily mined by The Doe Run Company. From 1960 to 2022, The Doe Run Company has reported that nearly 315 million tons of ore has been extracted from the Viburnum Trend.

Year	Democrat		Republican		Third Party
	#	%	#	%	#	%
2020	14,510	20.83%	54,183	77.78%	965	1.39%
2016	13,456	21.24%	47,521	75.01%	2,372	3.74%
2012	21,196	35.53%	37,046	62.09%	1,420	2.38%
2008	27,890	43.69%	34,795	54.50%	1,158	1.81%
2004	26,282	43.26%	34,061	56.06%	414	0.68%
2000	23,481	44.04%	28,556	53.56%	1,277	2.40%
1996	25,135	49.72%	17,817	35.24%	7,601	15.04%
1992	26,804	49.40%	16,727	30.83%	10,729	19.77%
1988	23,744	50.05%	23,561	49.67%	134	0.28%
1984	21,189	42.90%	28,207	57.10%	0	0%
1980	23,329	44.41%	27,817	52.95%	1,389	2.64%
1976	25,909	56.69%	19,568	42.81%	229	0.50%
1972	14,673	35.35%	26,830	64.65%	0	0%
1968	17,125	39.70%	20,689	47.96%	5,327	12.35%
1964	28,062	64.04%	15,760	35.96%	0	0%
1960	19,603	42%	27,066	58%	0	0%
1956	21,208	45.02%	25,903	54.98%	0	0%
1952	22,700	47.56%	24,974	52.32%	59	0.12%
1948	22,019	55.88%	17,300	43.90%	88	0.22%
1944	19,971	49.12%	20,630	50.74%	55	0.14%
1940	24,156	49.54%	24,515	50.28%	87	0.18%
1936	24,077	54.27%	20,067	45.23%	218	0.49%
1932	24,822	60.51%	15,836	38.60%	365	0.89%
1928	13,859	37.84%	22,674	61.91%	90	0.25%
1924	16,619	49.22%	16,399	48.57%	745	2.21%
1920	15,986	46.82%	17,619	51.61%	535	1.57%
1916	11,384	51.45%	10,262	46.38%	479	2.16%
1912	9,225	47.85%	7,228	37.49%	2,825	14.65%
1908	10,166	46.97%	10,675	49.32%	803	3.71%
1904	9,129	47.73%	9,537	49.87%	319	1.67%
1900	10,056	53.36%	8,575	45.51%	213	1.13%
1896	9,866	56.52%	7,527	43.12%	64	0.37%
1892	8,681	57.71%	6,102	40.56%	260	1.73%
1888	8,878	56.48%	6,485	41.25%	357	2.27%
1884	8,097	61.16%	5,055	38.19%	86	0.65%
1880	7,964	64.38%	4,160	33.63%	246	1.99%
1876	7,697	68.82%	3,461	30.94%	27	0.24%
1872	4,822	62.91%	2,843	37.09%	0	0%
1868	2,199	54.31%	1,850	45.69%	0	0%
1864	717	24.41%	2,220	75.59%	0	0%
1860	2,380	43.19%	211	3.83%	2,920	52.98%
1856	2,481	57.13%	0	0%	1,862	42.87%
1852	1,594	60.38%	1,046	39.62%	0	0%
1848	1,497	54.02%	1,274	45.98%	0	0%
1844	1,588	54.35%	1,334	45.65%	0	0%
1840	1,312	54.58%	1,092	45.42%	0	0%
1836	703	58.29%	503	41.71%	0	0%
1832	Incomplete returns		Incomplete returns		Incomplete returns
1828	816	70.89%	335	29.11%	0	0%

• Carbonate hosted lead zinc ore deposits
• Doe Run Company
• Missouri Mines State Historic Site
• St. Joe State Park
• Mississippi River and Bonne Terre Railway

• Missouri Mines State Historic Site
• Map of the Mineral resources of Missouri PDF

37°30′N 90°30′W / 37.5°N 90.5°W / 37.5; -90.5