Lock and Dam No. 21

lock and dam on the Mississippi River at Quincy, Illinois, USA
Place lock Q1867486
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Lock and Dam No. 21

Summary

Lock and Dam No. 21 is a lock[1]. It draws 4 Wikipedia views per month (lock category, ranking #20 of 89).[2]

Key Facts

  • Lock and Dam No. 21 is located in Melrose Township[3].
  • Lock and Dam No. 21 is located in Marion County[4].
  • Lock and Dam No. 21 is in the country of United States[5].
  • Lock and Dam No. 21's image is recorded as Mississippi River Lock and Dam number 21 HAER.jpg[6].
  • Lock and Dam No. 21's instance of is recorded as lock[7].
  • Lock and Dam No. 21's instance of is recorded as dam[8].
  • Lock and Dam No. 21's instance of is recorded as historic district[9].
  • Lock and Dam No. 21's architect is recorded as United States Army Corps of Engineers[10].
  • Lock and Dam No. 21's Commons category is recorded as Mississippi River Lock and Dam number 21[11].
  • Lock and Dam No. 21's coordinate location is recorded as {'lat': 39.9061, 'lon': -91.4322}[12].
  • Lock and Dam No. 21's Freebase ID is recorded as /m/0261yfm[13].
  • Lock and Dam No. 21's NRHP reference number is recorded as 04000181[14].
  • Lock and Dam No. 21's located in/on physical feature is recorded as Mississippi River[15].
  • Lock and Dam No. 21's heritage designation is recorded as National Register of Historic Places listed place[16].
  • Lock and Dam No. 21's GeoNames ID is recorded as 4243351[17].
  • Lock and Dam No. 21's elevation above sea level is recorded as {'unit': 'Q11573', 'amount': '+143'}[18].
  • Lock and Dam No. 21's drainage basin is recorded as Mississippi River drainage basin[19].
  • Lock and Dam No. 21's archINFORM project ID is recorded as 80739[20].
  • Lock and Dam No. 21's LoC HABS/HAER/HALS place ID is recorded as il0554[21].
  • Lock and Dam No. 21's National Inventory of Dams ID is recorded as MO10304[22].

Body

Geography

Lock and Dam No. 21 is in the country of United States[5]. Located in include Melrose Township[3], a township of Illinois[23], in United States[24] and Marion County[4], a county of Missouri[25], in United States[26], founded in 1826[27], headquartered in Palmyra[28].

Physical Characteristics

Lock and Dam No. 21's elevation above sea level is recorded as {'unit': 'Q11573', 'amount': '+143'}[18].

Designation and Status

Recorded instance of include lock[7], dam[8], and historic district[9]. Lock and Dam No. 21's heritage designation is recorded as National Register of Historic Places listed place[16].

Why It Matters

Lock and Dam No. 21 draws 4 Wikipedia views per month (lock category, ranking #20 of 89).[2]

References

Programmatic citations — every numbered marker resolves to a verifiable graph row below.

Direct Wikidata claims

  1. [5] . wikidata.org.
  2. [6] . wikidata.org.
  3. [7] . National Inventory of Dams. wikidata.org.
  4. [8] . National Inventory of Dams. wikidata.org.
  5. [9] . wikidata.org.
  6. [10] . wikidata.org.
  7. [3] . wikidata.org.
  8. [4] . wikidata.org.
  9. [11] . wikidata.org.
  10. [12] . wikidata.org.
  11. [13] . wikidata.org.
  12. [14] . wikidata.org.
  13. [15] . National Inventory of Dams. wikidata.org.
  14. [16] . National Register of Historic Places. Retrieved . wikidata.org.
  15. [17] . wikidata.org.
  16. [18] . wikidata.org.
  17. [19] . wikidata.org.
  18. [20] . archINFORM. Retrieved . archinform.net. Provenance: wikidata.org.
  19. [21] . wikidata.org.
  20. [22] . wikidata.org.

Inline context (facts about related entities)

  1. [23] . Wikidata. wikidata.org. → on this site
  2. [24] . Wikidata. wikidata.org. → on this site
  3. [25] . Wikidata. wikidata.org. → on this site
  4. [26] . Wikidata. wikidata.org. → on this site
  5. [27] . Wikidata. wikidata.org. → on this site
  6. [28] . Wikidata. wikidata.org. → on this site

Class ancestry

  1. [1] . Wikidata. wikidata.org.

Aggregate / graph-position facts

  1. [2] . Wikimedia Foundation. dumps.wikimedia.org.

📑 Cite this page

Use these citations when quoting this entity in research, articles, AI prompts, or wherever provenance matters. We aggregate Wikidata + Wikipedia + authoritative open-data sources; the stitched, scored, cross-referenced view is what 4ort.xyz contributes.

APA 4ort.xyz Knowledge Graph. (2026). Lock and Dam No. 21. Retrieved May 3, 2026, from https://4ort.xyz/entity/lock-and-dam-no-21
MLA “Lock and Dam No. 21.” 4ort.xyz Knowledge Graph, 4ort.xyz, 3 May. 2026, https://4ort.xyz/entity/lock-and-dam-no-21.
BibTeX @misc{4ortxyz_lock-and-dam-no-21_2026, author = {{4ort.xyz Knowledge Graph}}, title = {{Lock and Dam No. 21}}, year = {2026}, url = {https://4ort.xyz/entity/lock-and-dam-no-21}, note = {Accessed: 2026-05-03}}
LLM prompt According to 4ort.xyz Knowledge Graph (aggregator of Wikidata, Wikipedia, and authoritative open-data sources): Lock and Dam No. 21 — https://4ort.xyz/entity/lock-and-dam-no-21 (retrieved 2026-05-03)

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