WHEN PRESIDENT Reagan last year proposed an increase in fees for recreational use of national parks and other federal lands, the Office of Management and Budget wrote: "This administration is committed to the philosophy that those who benefit directly from a specific federal service should pay the costs of providing that service where charges can be reasonably applied." Though Congress rejected the proposal, the president is expected to revive it in this year's budget.

For another use of the federal domain, however, the White House apparently will not suggest an increase. By March 1 the administration must set new grazing fees for the western producers who raise cattle and sheep on federal lands. In prior years OMB had recommended to Mr. Reagan that these fees be raised to cover a greater share of costs. Environmentalists also want them raised; they say the fees are so low that they have encouraged overgrazing and denuded the land. But OMB director James Miller has now recommended that the grazing fees be frozen for a year instead.

His memo to the president made clear the reason. "The issue of the appropriate level of grazing fees on federal rangelands is of great political sensitivity," he wrote. Several of the Republican Senate seats regarded as vulnerable this year are in western grazing states, and Mr. Miller reminded the president that "recently 28 senators and 40 congressmen wrote to you" in behalf of a formula that beginning March 1 "would lower the grazing fees . . . by 22 percent."

OMB describes the Miller position as a compromise in that it would stave off a cut. It would also have the virtue of temporarily tossing the political burden of writing a new fee formula back to Congress, which last year tried to work out a compromise on the issue but failed. The memo suggests that the president, in announcing the freeze, also announce his intention "to continue working with Congress" in behalf of "a statutory formula." The administration's "initial position," Mr. Miller said, would be that federal fees should be the same as for use of comparable private lands, though "we would expect" Congress finally to vote for less.

Then why temporize? The current fee structure is a parochial subsidy that benefits about 31,000 producers, including some very large ones, bunched in a few western states. The national meat and wool supplies are not at stake; the matter is much more one of private gain than public need. In a year when so many other forms of federal support are in jeopardy, there is no excuse for exempting these. The president keeps saying that if Congress can't bring itself to make the hard decisions, the least it could do is give him the power to make them instead. Here he already has the power. He should use it.