What's the difference between the National Guard and the Reserves?

That question has been asked frequently as the number of Utahns involved in Operation Desert Shield keeps climbing.Both groups of part-time soldiers are part of the Pentagon's "Reserve Component," but members of each branch use the word "reserve" more selectively to help distinguish the different elements of military service.

"The major difference between the National Guard and the Reserves is that the National Guard has a state mission in addition to its federal mission," said Maj. Bob Nelson, spokesman for the Utah National Guard.

The National Guard's state mission "is to serve the governor and the state in times of natural emergency or civil disobedience or on other projects. In that situation, the governor is commander in chief," Nelson said.

Since many of the National Guard's training missions have civilian applications, Guard members often use their bulldozers, helicopters and other equipment to help build roads, seek out drug smugglers and other tasks directed by the state.

"We also have a federal mission, which is identical to the federal mission of the Reserve, and in that instance the president is our commander in chief," Nelson said.

Operation Desert Shield has brought the president's role to light, and his authority to take the civilian solders away from their non-military jobs and turn them into full-time soldiers for 90 days. That authority can be extended to 180 days of active duty, and Congress earlier this month gave the president authority to call National Guard and Reserve soldiers for 360 days - but only in the case of combat units. Congress can further extend Reserve and National Guard members' duty under a declaration of war or emergency.

The National Guard operates with Army and Air Force components, while the Reserves incorporate all branches of the military: Army, Air Force, Navy, Marines and Coast Guard.

The Coast Guard is the most unique of the Reserve elements in that its full-time and Reserve components operate under the routine direction of the U.S. Department of Transportation. The Coast Guard can be transferred to Defense Department control in a wartime situation.

And while Utah might not seem like a likely place to find a Coast Guard unit, Salt Lake City's "Salty Coasties" take pride in the fact that they train on the saltiest water of any of the United States' Coast Guard units.