More than 80 percent of the soldiers in Utah's Army Reserve and Army National Guard have now been deployed, officials say. And with the May departure of the 872nd Ordnance Company, all large Utah-based units have had one tour or more.

The strain on Utah troops, mirrored nationally, is further indication of problems facing the Pentagon as U.S. military actions continue in Iraq and Afghanistan, where up to 35 percent of the troops have been reservists.

Under Defense Department directives, soldiers are not to serve more than 24 cumulative months on active duty. Reserve deployments typically last about 18 months - and defense officials say six-month deployments for part-time troops aren't likely.

But that doesn't mean reservists expect a reprieve. Officials note the Pentagon's policy can change to match federal law, which doesn't place a maximum on the amount of time reservists can spend on active duty during a state of emergency. And some are saying the policy will indeed have to change as U.S. military commitments in the Middle East continue.

A Government Accountability Office report released Tuesday concluded half of all Army Reserve soldiers have already been mobilized or alerted for future missions. Many of the remaining soldiers are untrained, medically disqualified or performing "critical" homeside duties such as recruiting.

Just 16 percent are eligible for further deployment, the report says.

The lack of soldiers available under the Pentagon's directive may help explain a recent lull in reserve call-ups. The Pentagon announced this week the number of mobilized reservists has fallen to about 138,000 - down from a high of 220,000 in 2003.

Pentagon officials say the number may drop even further in coming months. But Lt. Col. Bob Stone, a Defense Department spokesman for Reserve affairs, said there is no crisis in the availability of citizen soldiers.

"There are 1.1 million members in the ready reserve," Stone said. "Since Sept. 14, 2001, we have mobilized just under 500,000."

But among those who have not yet been called up are a large number of Naval, Coast Guard and Air Force reservists, whose training does not match the Pentagon's current needs in Iraq and Afghanistan. Sailors and airmen comprised just over 10 percent of the reservists on active duty as of July 7.

Where possible, the Pentagon has assigned members of the Navy, Air Force and Coast Guard to nontraditional roles.

"Right now, you have Air Force transportation units delivering supplies in Iraq and Kuwait," Stone said. "Back in the Cold War, that would have been shocking."

But there is only so much the Army and Marine Corps' sister services can do to support a ground combat-oriented mission.

The rest falls upon active duty units - which are expected to increase their share of the forces in Iraq and Afghanistan 5 percent by next year - and to people like Horace Hill.

In May, when Utahns from the 872nd gathered in Ogden for predeployment briefings, the chief warrant officer was there to meet them. A New Yorker and 19-year veteran of the Army Reserve who had not yet been called into active duty, Hill volunteered to fill a slot in the unit's supply division.

"I want to be able to say I've done my duty, and then be back with my family," he said.

With recruiting, retention and training difficulties leaving many deploying units at less than full strength, Guard and Reserve commanders are increasingly looking outside their own units for soldiers.

Between September 2001 and March 2005, the Army Reserve transferred about 53,000 soldiers from nonmobilizing units to mobilizing units, according to the GAO report.

Much of that "shopping" is done in Utah, where recruiting woes have not been as bad as in other places and soldiers are known for volunteering to serve a second tour sooner than they must.

That, of course, sometimes leaves Beehive State units at less-than-deployment strength. And so those units must also send a request up the chain of command to find soldiers elsewhere.

When the 872nd deployed, for instance, it did so with soldiers from Hill's home state of New York, along with others from Arkansas, California, Colorado and New Jersey.

But the GAO report indicates it is getting harder to find the right mix of soldiers and specialists to keep Reserve units that are still eligible to deploy able to do so. And equipment shortages are further complicating the task.

Just as soldiers are moved from unit to unit, so too goes military machinery - more than 236,000 pieces of which have been transferred between commands since September 2001, according to the GAO. The report notes that in war zones equipment is heavily used, often well past its typical life span.

Scott Quimby, senior civilian for operations at the Salt Lake City-based 96th Regional Readiness Command, said Army Reserve units also are losing equipment when they depart the war theater, as commanders in Iraq and Afghanistan request those units leave behind vehicles, weapons and other machinery for the next unit.

Equipment that returns to the United States with reserve units goes through a yearlong "reconstitution" process to bring it up to Army standards. That process further limits what supplies are available, Quimby said.

"It's just a big jigsaw puzzle," Quimby said. "What we can't put together but can't do without we go out and borrow."

Utah units typically leave the state with about 90 percent of the required equipment. Last-minute wrangling results in a full equipment checklist by the time each unit leaves the United States, Quimby said.

"We try to look way ahead, always at the next rotation and the one after that," he said.

For the units most likely to be called up next, Quimby said, "we're already trying to fill shortages, so we have the least amount of hectic equipment swapping at the last moment."

mlaplante@sltrib.com