It marks the latest sign that an already-booming wind industry is starting to trickle west across the Cascade Range.

Horizon Wind Energy, which also is proposing a 120-megawatt project currently under court challenge by Kittitas County officials, filed an application to lease 5,400 acres from the state Department of Natural Resources in the Larch Mountain area of Clark County.

By meeting a Monday deadline, Horizon will vie for the lease in an auction with a Portland-based subsidiary of enXco Inc.

Operating as Evergreen Wind Power Partners, enXco applied for a lease last month. The DNR, using the same process by which it auctions timber sales, expects to hold the auction in its regional office in Castle Rock after it conducts a preliminary review of any environmental issues.

"It will be a generic overview," said Michelle Metcalf, an agency specialist in Castle Rock.

Horizon's project manager in Portland said the company filed its application as a placeholder while it researches the site's wind energy potential.

"It's not a site we know a lot about," project manager Dana Peck said.

Horizon's application suggested a wind project producing between 85 and 200 megawatts of energy, with 45 to 70 turbines. (For perspective, Clark Public Utilities' natural gas-fired power plant near Vancouver Lake generates 248 megawatts - roughly half the energy needed to keep the lights on in Clark County.)

State lands Commissioner Doug Sutherland has encouraged companies to take a look at state-owned forestland in Western Washington, citing wind energy as a good opportunity for the state to earn money for school construction while boosting the development of renewable energy. Most wind energy development of the past several years has occurred in farm fields and pastures east of the Cascades.

There are several reasons for that, according to a representative of Energy Northwest, a consortium of Washington public utilities.

Brad Peck, public information officer for the consortium, noted that the forested and mountainous terrain of Western Washington makes it tougher to build the roads necessary to transport and assemble massive towers that can rise 400 feet.

In addition, there may be economic constraints even for the few trees that would have to be removed to accommodate each relatively small concrete tower footing.

"I am told the value of the timber production is relatively higher than the dry-land grains on the eastside, so it is not as compelling financially for the landowners," Peck wrote in an e-mail.

Energy Northwest has nonetheless decided to make a go of it near Naselle in Pacific County.

The consortium last year signed a lease agreement with DNR to build a wind farm on an old military installation known as Radar Ridge. The consortium agreed to pay the state $2,500 for each megawatt of capacity on the wind turbines it expects to install by 2011. That would amount to $50,000 for a 20-megawatt project.

Then, there is the matter of annual rent.

Energy Northwest agreed to pay $4,347 for each megawatt of rated capacity during each of the first 10 years of operation (generating $86,940 for state coffers on a 20-megawatt wind farm), followed by an ascending scale that rises to $6,168 after the 36th year.

Since then, Metcalf said, the state has changed to extracting royalty payments on a percentage of gross revenue.