为每个区域填色
颜色深浅代表数值。适合比率、占比和人均指标——这些数字已经消除了面积和人口规模的影响。
打开模板全部地图
Maryland County Map Maker
A blank Maryland county map to print, and a builder to fill it with your own data. Download the free outline of all 23 counties, or upload a spreadsheet and publish an interactive Maryland map you can embed anywhere.
Maryland 空白地图，免费下载
全部 23 个counties，线条干净的轮廓图。可打印、可填色、可放进文档——无需注册，也无需署名。
任何用途均可免费使用，包括商用与课堂。由编辑器所用的同一套边界数据生成。
下载 SVGMaryland 地图能看出什么
Maryland is drawn in 23 counties, plus Baltimore City, which is not a county at all — it is an independent city that has stood outside county government since 1851, and it is the single most important thing to know before you put data on this map. The shape of the state does the rest of the explaining. Garrett and Allegany sit in the Appalachian west, closer to Ohio than to the Atlantic. The centre holds almost everyone: Montgomery and Prince George's along the District line, Baltimore County wrapped in a horseshoe around the city it no longer contains, Anne Arundel and Howard filling the space between Baltimore and Annapolis. Then the land thins out again across the Chesapeake into nine Eastern Shore counties where a whole county can hold fewer people than a Bethesda zip code. A Maryland county map is therefore a map of one dense middle and two quiet ends, and the counties in that middle are small enough on the page that a shading scale has to work hard to make them readable at all.
Maryland 的三种画法
数值是比率时给区域填色，是计数时用大小不同的标记。把这两者用反，是数据地图最常见的误导方式。
什么时候该画 Maryland 地图
Your data is reported by Maryland county
Maryland Department of Health indicators, Department of Labor unemployment figures, State Board of Elections returns, MSDE school data and the state's own open-data portal all publish by county and Baltimore City.
You are showing a rate or a share
Median household income, uninsured rate, vaccination coverage, share of the vote, change since the last census. Rates already account for population, which is exactly what a shaded region needs.
You want to show the DC and Baltimore pull
Two metros dominate the state from opposite ends of one corridor. Montgomery and Prince George's face Washington, Baltimore County and Anne Arundel face Baltimore, and the counties between them behave like neither. Geography is the clearest way to say that.
You need a blank map to print or fill in
Classroom work, canvassing plans, territory splits, colour-by-hand sessions. The free outline above prints cleanly at any size.
什么时候不该画 Maryland 地图
Your data separates Baltimore City
Most Maryland datasets report 24 jurisdictions. This geography draws 23 counties, so a city row has nowhere to land — merge it into Baltimore County and say so in the caption, or use a symbol map that can place a marker on the city.
You are mapping totals rather than rates
Shade by a raw count and Montgomery and Prince George's win every time — between them they hold roughly a third of the state. Anything that grows simply because more people live there belongs on a sized symbol.
Your unit is a legislative district or a school system
Maryland's legislative districts cross county lines freely, and while most school systems are county-wide, Baltimore City's is not. Forcing either onto counties misplaces the thing you are describing.
The story is inside one county
Montgomery County alone holds about a million people, and the difference between Silver Spring and Poolesville is invisible at this scale. Sub-county data wants zip codes, census tracts or a plain ranked table.
如何制作 Maryland 地图
从表格到发布上线，一步一步来。
Download the blank map, or start from the template
The free outline above is a plain SVG of all 23 counties — print it, or drop it into a document. To build with data, open the PlotSet Maryland (counties) template, which comes with sample data already bound.
Prepare a county column and a value column
One row per county: the county name or its five-digit FIPS code in the first column, your number in the second. Maryland FIPS codes all begin 24.
Decide what happens to Baltimore City
Do this before you upload, not after. Either fold the city into Baltimore County and label the map accordingly, or drop the row and note the omission. A silently missing city is the most common way this map misleads.
Upload or connect your data
Import a CSV or Excel file, paste from a spreadsheet, or connect a Google Sheet so the map can be refreshed when the source updates.
Pick the style that fits the measure
Shade the counties for a rate, or switch to symbols or bubbles for a count. Bubbles are often the better choice here, because the small central counties hold the large numbers.
Publish, embed or export
Publish for a live interactive map with a tooltip on every county, or export a PNG, SVG or PDF for a report or a deck.
从已加载示例数据的 Maryland 模板开始，再换成你自己的数据。
打开模板让 Maryland 数据正确匹配
地点列应该长什么样，以及去哪里找现成能对上的数据。
Twenty-three counties, twenty-four jurisdictions
Baltimore City is independent of Baltimore County and is reported separately by almost every state agency. This geography has a Baltimore County shape and no Baltimore City shape, so the two must be reconciled in your spreadsheet.
Apostrophes and spelled-out saints
The map expects Prince George's, Queen Anne's and Saint Mary's — not Prince Georges, Queen Annes or St. Mary's. Smart quotes pasted from a document are a different character again, and a mismatch leaves a blank county rather than an error.
Maryland FIPS codes start at 24
24001 is Allegany, 24047 is Worcester, and 24510 is Baltimore City — the odd one out, numbered in the independent-city range. Store the column as text so the leading 2 survives.
Where to get Maryland county data
The Maryland Open Data Portal, the Maryland Department of Health, the Department of Labor, the State Board of Elections and the Census Bureau's ACS all publish county-level tables.
Maryland 地图上的常见错误
Losing Baltimore City without saying so
Join 24 rows to 23 shapes and one row vanishes quietly — and it is the row holding several hundred thousand people and, usually, the extreme value. Check your row count after the join, every time.
Shading counts instead of rates
It produces a population map: the three counties around Washington and Baltimore glow, the Eastern Shore disappears, and the reader learns nothing they did not already know.
Letting the western counties carry the eye
Garrett and Allegany are large on the page and small in population. A striking colour out there dominates a map that is mostly about the corridor, so suppress low-count counties explicitly or note the caveat in the caption.
Trying to label all 23 counties
The central counties are too small on screen for a label to fit. Label the handful your argument rests on and let the hover tooltip carry the rest.
Maryland 地图常见问题
Yes. The outline above is a free SVG of all 23 Maryland counties — right-click to save it, print it, or drop it into a worksheet or document. No account needed.
把你的数据放到 Maryland 地图上
上传表格，几分钟内发布一张交互式地图——免费，无需信用卡。