WASHINGTON — Sen. Ron Wyden, D-Ore., blasted the U.S. Forest Service Thursday for asking rural counties in Oregon to return an additional $400,000 of timber funds to the federal government.

Last week, the Forest Service sent letters to individual states, saying that additional cuts to payments under the Secure Rural Schools program were necessary because of mandatory spending cuts required under sequestration.

In March, the agency announced it was seeking to reclaim $18 million in timber payments nationwide, including $3.6 million from Oregon counties.

Including the cuts announced last week, Oregon’s total SRS funds in fiscal year 2012 will be $4 million less than expected.

In a letter Thursday to Secretary of Agriculture Tom Vilsack, Wyden voiced frustration at how the Forest Service, a branch of the Department of Agriculture, has “bungled” its efforts to recover money it already distributed.

“I am astounded by the lack of agency clarity, the apparently arbitrary decision to disproportionately target Oregon’s SRS funds, and the aggressive agency approach that has characterized this ordeal. I can only conclude that USDA and the Forest Service are continuing their campaign against cash-strapped rural counties,” Wyden wrote.

A Forest Service spokeswoman said Thursday the agency does not comment on correspondence with members of Congress.

Last year, Oregon received almost $100 million in timber payments, including $36 million from the BLM for the 18 counties in Western Oregon containing Oregon and California Railroad Co. lands. Deschutes County received $1.8 million, Crook County $1.7 million and Jefferson County $570,000.

Congress first enacted the Secure Rural Schools program in 2000 to compensate heavily forested counties whose local economies were devastated by federal limitations placed on logging on public land. The payments, designed to grow smaller over time, were meant to help portions of local budgets, including spending on schools and roads, normally supported by the tax base until the region could develop a non-timber-based economy.

Secure Rural Schools payments are authorized under three sections. Title I payments are for schools and roads, and Title III funds are dedicated for local fire prevention efforts. Title II funds are allocated for special restoration projects, and the Forest Service holds on to those funds until specific projects are approved.

The Forest Service is focusing its efforts on recovering as much as possible from Title II funds, which would mean some counties would not have to return any of the money they have already received.

According to the Forest Service’s letter, it will take all $4 million of repayments from Oregon’s Title II funding, leaving the state with only $3.4 million to spend on restoration projects.

In his letter, Wyden maintained that Oregon was singled out because it had a relatively large amount of Title II funds.

“Apparently, in deciding how to seek additional repayments, the Forest Service arbitrarily increased the burden on some states — specifically those with more Resource Advisory Committee (RAC) funds,” he wrote. “This has resulted in Oregon bearing the lion’s share of the additional costs. All of this is coming at a time when Oregon’s counties are among those hardest hit by the decline in payments — in many places having to cut basic county services and eliminating sheriff’s patrol, 911 services and roads work.”

By contrast, Alaska was asked to return only $100,000 in the latest round of cuts.

Wyden called for the Forest Service to provide a “clear accounting” of why the additional repayments are necessary, and suggested the agency apply them equally across SRS counties at a flat rate.