In most cases, a decision to let forest fires burn themselves out as long as they don't endanger nearby communities makes good environmental sense. A team of federal experts endorsed that policy the other day - with some important refinements.

The "let-it-burn" policy came under serious criticism this past summer and fall as out-of-control flames raged through much of Yellowstone Park. Afterwards, a study was launched to review the whole issue.Fortunately, the federal team did not let itself be stampeded by criticism into abandoning a normally sensible and scientifically sound policy.

The study said that forest fires are so helpful in an environmental sense that there ought to be more of them, including some set deliberately by man. Burned over areas usually grow back quickly and are more robust and healthy because dead trees and vegetation are gone.

At the same time, the experts emphasized that any fire ought to be carefully monitored and quick action taken in certain circumstances.

As the Deseret News pointed out last July, there may be forest fire situations in which a let-it-burn policy no longer makes sense. That point clearly was passed in the Yellowstone fire.

Essentially, that is what the new federal study is saying. The Yellowstone fire turned into such a monster because severe drought conditions made the "let-burn" policy inadequate. It caught people by surprise. In addition, there apparently was some confusion among fire managers about rules and policy - and who would decide when to abandon the let-burn policy.

The federal study team has drawn up a list of detailed recommendations about the factors to be considered in any fire, including drought conditions, the availability of fire-fighting resources, the existence of other fires in the region, and the decision-making process to be followed.

In all cases, the team said, each fire is to be closely monitored and kept within well-defined limits. A fine line must be walked between letting a forest fire burn and seeking to extinguish it as quickly as possible.

It's not likely that the circumstances that led to last summer's conflagration will be repeated soon, but the hard lessons learned in those Fires should be studied and applied from now on.