Network with local residents. Ask about current ownership, previous ownership, roads, land use and easements. Write down all information you obtain.
Contact the city or town clerk where you live. Tell him you would like to obtain a map and share with him the description of the acreage as well as the most recent ownership.
Talk with your local property assessor. Describe the location of the acreage and its ownership if known. Ask how you might view a copy of the property assessment map for that acreage. Ask to purchase a copy.
Contact your local recorder, whose office usually is in the courthouse of the county in which the acreage is located. Describe the location of the acreage as best you can and ask questions about available maps. Ask to see survey records and plat maps related to the acreage. Ask about recorded easements and related maps. Inquire as to ownership of the acreage. Ask about online resources in your area for obtaining acreage maps. Purchase any maps related to the acreage you are investigating.
Call the local planning board or attend one of their meetings. Ask if the board might have a subdivision map or other map related to the acreage.
Go to the official website for your state's property tax records. From there, you may be able to link to a site that has property ownership maps and information.
Talk with your local county extension agent and weed control board as well as the closest Bureau of Land Management office. Describe the acreage and ask their recommendations for obtaining maps.
For historical acreage map research, contact the historical societies in your state as well as the historical libraries located on university campuses. Tell them your needs and ask their recommendations. Visit in person to conduct further map research. Request copies of maps you find. Explore the services of the Bureau of Land Management records websites.