John Due House

River Hill is the last and westernmost village to be developed in the town of Columbia, Maryland, United States, though some residents maintain addresses in Clarksville. The village is home to 6,520 residents in 2,096 housing units in 2014. The area was used as a game preserve by James Rouse to entertain clients and personal hunting during the buildout of the Columbia project. In 1976, County Executive Edward L. Cochran selected the 784-acre parcel owned by Howard Research and Development for an alternate location for a county landfill; a task force selected Alpha Ridge Landfill instead. Residential construction started in 1990. It is bounded by Maryland Route 108 and Maryland Route 32, and is centered on Trotter Road. The village is divided into two neighborhoods: Pheasant Ridge and Pointers Run, with about 6,500 residents.The original plan called for the village to be connected to the rest of Columbia via an extension of Little Patuxent Parkway. In addition, a dam on the Middle Patuxent River would have created a large lake in that watershed. However, with the rise of the environmental movement, a large part of the watershed was made into a park, with approximately half of its acreage devoted to open space, which includes the 900 acres (3.6 km2) of the Middle Patuxent Environmental Area. In 1998, the county initiated managed deer hunting in River Hill, becoming the first time hunting was permitted in the Columbia development since the land purchases of 1963–1966. River Hill is largely disconnected from the rest of the city, accessing Columbia Town Center only by roads on the periphery of the city. The original plan called for 90 acres (360,000 m2) to be devoted to apartments, but the rural neighbors wanted a lower population density. The county zoning board decided upon 33 acres (130,000 m2) for apartments. Consequently, River Hill has the most open space of all the villages.

River Hill Farm is a historic slave plantation located in Clarksville in Howard County, Maryland, United States. River Hill Farm resided on a land tract patented as "Four Brothers Portion". The house was built in the 18th century out of field stone with stucco covering. Outbuilding included a slave quarters. The 500 acre property was the home of Major Henry Owings of Owingsville. In 1972, Rouse used the River Hill farm as a game preserve while other sections were being developed. Howard Research and Development placed the Game Manager lived in the historic house. In 1974 The property was proposed for use as a landfill, but Alpha Ridge Landfill was selected. The house was not preserved or submitted for the historic registry by the Rouse Company. It was demolished for the development of Pointers Run.

Welling's Stone House or Clifton is a historic stone house situated between Clarksville, Maryland and Fulton, Maryland. Clifton was built on a tract of 2500 acres of land patented as "White Wine & Claret" in 1702 by John Dorsey. The land was inherited by Dorsey's grandsons, Charles and William Ridgley. The tract was divided into an 820-acre tract for William Ridgley, 930 for Charles Ridgley, and 234 acres to John Ridgley. The house was situated along Guilford road, one of the region's earliest "rolling roads" where tobacco would be transported from slave plantations by rolling hogshead containers to docks at Annapolis. William Welling built the two and a half stories tall house with stone construction. The property was surrounded by 238 acres of farm fields until it was purchased by the Rouse Company division, Howard Research and Development for subdivision. A portion of the property was used for recreation vehicle parking for the Columbia development for several years. The barns were removed, and the address was changed to a cul-de-sac address on Warm Sunshine Path. The Welling cemetery has been fenced in with new gravestone markers.

The Middle Patuxent Environmental Area (MPEA) is a 1,021-acre (4.13 km2) wildlife area in Clarksville, Maryland and operated by the Howard County Department of Recreation and Parks. It is located next to the River Hill village in the town of Columbia, Maryland, in the United States. The MPEA was created in 1996 for educational, research, and recreational purposes.

River Hill High School is a public high school in Clarksville, Maryland, United States. It is part of the Howard County public schools system. River Hill High School was awarded a "gold medal" by U.S. News & World Report. It was recognized by BusinessWeek as having the "Best Overall Academic Performance" in Maryland. It was also ranked 4th of 225 High Schools in the State of Maryland as of 2018.It was rated the 165th best school in the nation by US News in 2013.

Worthington's Range, "Howard's Chance", "Howard's Range", or "Tierney Gambrel Roof House", is a historic slave plantation located between Clarksville, Columbia and Simpsonville in Howard County, Maryland, United States. Rachel Worthington ( - 1776) settled the site in 1753, carving out 369 acres of "Worthington's Range" from her husbands existing slave plantation. The house is the birthplace of Paul Griffith Stromberg. The "Miller Cemetery" lies about two hundred feet Northwest from the house. It was destroyed by arson in 1977.In 2014, former Howard County Department of Planning and Zoning director's firm Land Design and Development petitioned the planning board to subdivide the historic property and cemetery for a 150 unit housing development called "Enclave at Tierney Farm". Density was increased by having the county extend sewer service to the rural property. The project was delayed a single year because of an indefinite lack of school capacity in the region.

Clarksville is an unincorporated community in Howard County, Maryland; the second highest-earning county in the United States according to the U.S. Census Bureau. The community is named for William Clark, a farmer who owned much of the land on which the community now lies and served as a postal stop that opened on the 4th of July 1851.Some of the most expensive homes on the East Coast are located in or around the town, whose property values are among the highest in the country. According to the U.S. Census Bureau, Clarksville District 5 has a population of 56,239, with an estimated average income of $195,124, with median income of $160,606. As of 2023, the average annual household income in Clarksville is $248,722, while the median household income sits at $223,448 per year. The village of River Hill (which include Pheasant Ridge and Pointers Run), the newest addition to the Rouse Company development of Columbia, is adjacent to Clarksville. Clarksville's public schools, part of the Howard County public school system, are among the highest-ranked in the nation and often have significantly higher funding than competing private and charter schools. The area is located southwest of Baltimore and north of Washington, D.C., and many residents of Clarksville commute to work in one of these two cities or their nearby suburbs. Montrose and Richland Farm are listed on the National Register of Historic Places in 1973.

The James and Anne Robinson Nature Center is a nature education facility situated on 18 acres of park land adjacent to the Middle Patuxent Environmental Area. Geothermal heating/air-conditioning, porous paving, solar panels, water conservation methods and other features make this building environmentally-friendly and have earned it the LEED Certified Platinum designation. Each year, the Center runs over 450 programs including field trips, public programs, birthday parties, home school and scout programs. James and Anne Robinson cared for the property for decades and kept it from being used by developers, ultimately arranging transfer to Howard County, Maryland for enjoyment by the general public. The Center continues to be partially supported by the James & Anne Robinson Foundation and is owned and operated by the Howard County Department of Recreation & Parks.

Hatfield Safe House, or Simpsonville Mill Miller's House is a historic home located at Columbia, Howard County, Maryland, United States.The three-story wood-framed house is three bays wide and one bay deep on a 9-acre parcel. A house was built on a stone foundation built in 1755 for a possible grist mill. It is known as a safe house for the Underground railroad. The original structure burned down, with a new frame building built on the original foundation. From 1865 to 1878 it was owned by William Braysahaw. In 1878, James Simpson resided at the residence to which "Simpsonville" is named. In the late 1920s the terraced landscape was dotted with chicken coops. From 1909 to 1934 the house was the residence of county commissioner William W. Inglehardt. The building is a component of Simpsonville Historic District.

Walnut Grove is a historic plantation home located in Clarksville, Maryland, Howard County, Maryland. The Walnut Grove plantation was built on land patented by Thomas Browne as Browne's Chance and Dorsey's Friendship. Revolutionary war patriot Col Gassaway Watkins built the stone manor house in 1780 with an onsite cemetery. The property was also owned by racetrack & farm owner John Gill and son Barry Gill In 1979 the property was entered into a historic preservation easement, with the intent to develop after a 25-year review. In 2001, the owners of Walnut Grove proposed developing 202 acres of the site near Sheppard Lane to develop 101 housing units with Goodier Builders.

Haysfield Airport - MD24 was an airport located in Howard County, Maryland

Howard County General Hospital is a 225-bed, not-for-profit health care provider located in Columbia, Maryland.