The U.S. Geological Survey (USGS) is expanding the involvement of volunteers to enhance data collection for The National Map.

The program, known as The National Map Corps, focuses on encouraging the public to collect data relating to structures by adding features and/or correcting existing data within The National Map database. These structures can include schools, hospitals, post offices, police stations and other public places.

Collaborative pilot projects in Colorado were recently used to test the concept of crowd-sourcing. While the project is ongoing, early indications point to positive results using the volunteers.

Over a trial period of 10 months, 143 volunteers collected, improved or deleted data on more than 6,400 structures in Colorado. The volunteer-collected data showed an improvement of about 25 percent in both location and attribute accuracy for existing data points.

These results have led to a phased, nationwide expansion of the crowd-sourcing volunteer project. The states in the first expansion are Arkansas, Alaska, Colorado, Delaware, Georgia, Idaho, Maryland, Michigan, Montana, North Dakota, New Jersey, New Mexico, Ohio, Oregon, South Carolina, Utah, Washington and West Virginia.

After an evaluation of the quality and procedures of the first group of states, the second set will be made available. Ultimately, by the end of 2013, the third batch of states will complete the program.

"The response by volunteers in Colorado exceeded our expectations both in terms of the number of volunteers and the quality of the data they collected,” said Kari Craun, the director of the USGS National Geospatial Technical Operations Center. “The volunteered geographic information community represents a fantastic, untapped resource to assist USGS in maintaining data that are part of The National Map.”

Without a network of volunteers, the desired information would not be collected this year and the existing data would not be updated, USGS said. Interested parties can become volunteers on The National Map website.