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The length of the canadian us border
Executive Summary
The most consistently reported figure for the full length of the Canada–United States international boundary is 5,525 miles (8,891 km); that total combines the contiguous U.S.–Canada border and the Alaska–Canada frontier and appears across government and reference compilations [1] [2] [3] [4]. Alternative breakdowns and partial‑boundary figures appear in the record: about 3,987 miles is frequently cited for the contiguous U.S. border excluding Alaska, while 1,538 miles is cited for the Alaska–Canada segment, and some sources emphasize other definitions that yield smaller land‑only tallies [1] [5] [6]. This analysis extracts the key claims from the provided material, compares the differing totals, and explains why the variations exist, using the available source set as the evidentiary basis.
1. Why 5,525 miles keeps appearing — the headline number that reporters use
The number 5,525 miles (8,891 km) is the recurring headline because multiple reputable compilations and boundary authorities adopt it as the comprehensive length of the international boundary between Canada and the United States. These compilations explicitly combine the long Alaska–Canada frontier with the border stretching from Maine across the Great Lakes to the Pacific, producing a single all‑inclusive figure [2] [3] [4]. Government and longstanding reference sources reflected in the set provided, including the International Boundary Commission references cited within those summaries, underpin the 5,525‑mile total, which is why it dominates public accounts and encyclopedic entries [2] [3]. The repeated cross‑citation between academic, governmental, and popular sources within this dataset creates strong corroboration for the all‑inclusive figure [4].
2. The split numbers that explain apparent contradictions — contiguous U.S. vs. Alaska
Sources in the set break the boundary into parts, generating the frequent statement that the contiguous U.S.–Canada border is approximately 3,987 miles, while the Alaska–Canada border adds another 1,538 miles, summing to the familiar 5,525‑mile total [1]. That decomposition explains why some references or conversations mention a roughly 4,000‑mile U.S. border: they are excluding Alaska and tracking only the lower‑48 adjacency. The dataset explicitly reports both the segmented and aggregate views, showing that the apparent contradictions are not competing facts but different measurement scopes [1] [7]. Recognizing which scope an author uses (all boundary vs. contiguous U.S. only) resolves most of the numeric confusion evident across sources.
3. Land‑only versus “land, lake, and sea” definitions — how measurement choices move the needle
Some sources in the collection highlight that different counting methods produce distinct totals because the boundary runs through terrestrial stretches, lakes (including the Great Lakes), and maritime limits. One provided entry frames a land‑boundary figure of 3,999 miles (6,435 km) for a particular land section from Passamaquoddy Bay to the Strait of Juan de Fuca, demonstrating that excluding certain water or maritime components or including only specific contiguous segments changes reported lengths [6]. The presence of Great Lakes and coastal segments means the boundary can be characterized as a land boundary, a hydrographic boundary, or a complete international border, and the selection of those categories determines which number is accurate for that formulation [6] [5].
4. Source provenance and dates — who’s saying what and why that matters
Within the available material, government compilations and boundary commissions are the backbone for the 5,525‑mile total, while alternative figures come from narrower institutional tables or specialized geographic treatments [1] [5] [6]. The dataset includes references to the U.S. Census and government tables, along with encyclopedia and geography sites; those entries frequently cross‑reference one another, indicating a consensus on the all‑inclusive figure while documenting the basis for segmented alternatives [5] [3]. Understanding the provenance—whether a source is summarizing International Boundary Commission data, a census table, or a popular geography page—clarifies why each figure is presented and helps avoid misinterpretation [2] [4].
5. Practical takeaway — how to cite the border length accurately depending on context
If the intent is to state the total international boundary between Canada and the United States, cite 5,525 miles (8,891 km) as the authoritative all‑inclusive length; that is the figure consistently used by boundary and reference compilations in this set [2] [3]. If specifying the lower‑48 (contiguous U.S.) boundary only, use roughly 3,987–3,999 miles depending on whether certain lake or maritime measures are included, and add the Alaska segment of ~1,538 miles when presenting a full national total [1] [6]. Be explicit about scope—all‑inclusive vs. contiguous vs. land‑only—because the discrepancy across the sources is methodological rather than contradictory [1] [6].