The dark lines on the map look like an enormous game of pick-up sticks played over Boulder County's mountains.

Scattered around Ward and Gold Hill, each line represents an unpatented mining claim on land owned, for now, by the Bureau of Land Management.

The future of those properties has been a hot topic since the BLM decided in the 1980s to dispose of its holdings in Boulder County. Last week, county officials announced their desire to acquire the final 2,500 BLM acres in Boulder County that have not yet been applied for.

Under a proposed plan, the county would purchase hundreds of BLM parcels as open space. The BLM would then use that money to help other agencies buy additional land sought for protection in the county.

But before the proposal becomes an official bid, months and possibly years of work wait ahead.

County officials say they are trying to move quickly to defend the BLM land from potential development. But some residents say they want to hear more about how much the land will cost and what restrictions will be placed on it before they can offer their support.

In 1986, BLM officials decided the agency's remaining lands in northeast Colorado were too scattered and too difficult to maintain. The parcels included about 3,000 acres in Boulder County, mostly near Ward and Gold Hill.

During the last several years, the agency has reached an agreement with the town of Ward to dispose of about 500 acres. That land has been deemed appropriate for "recreation and public purposes" and is offered at no cost under a federal act.

The remaining BLM land in the county is not currently designated for recreation and public purposes. This land includes 300 acres near Ward and roughly 2,200 acres surrounding Gold Hill.

Some of those properties are as small as 1/100th of an acre. Others are more than 150 acres in size.

Collectively the parcels represent a considerable potential holding for Boulder County. Commissioner Ron Stewart said the purchase would rank with major county mountain land deals, such as the 2,640-acre Caribou Ranch and 11,000-acre North Foothills Open Space properties.

"Not so much because it is a totally contiguous holding," he said of the BLM land. "But it's a significant piece of the central part of the mountain community."

According to the proposal, Boulder County would acquire the 2,500 acres near Gold Hill and Ward at "fair market value." That value is determined by a federal appraiser.

Once a fair market value is determined, the money spent by Boulder County would be used by the federal government to acquire "replacement" land for protection somewhere else in Boulder County.

As a result, Boulder County gets to acquire the BLM acres while land at equal value is preserved for control by other agencies such as the Forest Service.

But before any of these scenarios play out, more work must be done.

For starters, Boulder County would need to identify "replacement" land to be bought by the BLM. The process of finding both land and willing sellers could take months or years, said Jan Fackrell, a BLM realty specialist familiar with the Boulder County properties.

"It's quite a process to identify acquisition land," she said.

Fackrell said Boulder County's proposal has some appealing aspects. But she said the BLM was somewhat surprised at the timing of the announcement.

"We hadn't been given an indication their proposal was forthcoming," she said.

Stewart said the county's proposal at this point is to see if the "framework" for acquiring the BLM land is acceptable to the federal agency. Formal purchase prices — believed to be millions of dollars — and specific replacement land to be bought by the bureau would be determined later.

Money for the county's purchase would come from its open space fund, which is financed by a sales tax that voters approved in 1993.

Stewart said some of the BLM's parcels would be "problematic" for private development because of their slopes and access issues, but he said the county wants to ensure that no significant growth occurs on the other parcels.

"The question is, does the county government play a proactive role in trying to reduce that kind of development or do we sit by and let that happen?" he said.

Fackrell said the BLM will review the proposal and probably send it back asking for more specifics. In particular, the agency wants to know what replacement land would be proposed and how access through neighboring properties might be arranged.

Access is an important issue for several mountain landowners and property-rights supporters. Under arrangements with the BLM, property owners whose land can only be accessed by crossing BLM property generally are allowed access over the BLM land.

But some residents are concerned that if Boulder County takes control of those BLM properties, the commissioners may not be as willing to allow that access in the future.

"Right now, the BLM is very flexible in its use of allowing people to go ahead and do what they need to," said AJ Chamberlin, president of the Land Use Coalition. That group has been monitoring county land-use policies in recent months, particularly mountain policies.

Stewart didn't say specifically how the question of access might be discussed if the county acquires the BLM land.

"These are some of the issues that would have to be worked through as time goes on," he said.

Chamberlin said her group, which includes 1,000 landowners, will be researching the cost of the land over the next few months. She said members want to weigh the financial benefits of the county's buying all 2,500 acres, especially if some of it lies on land too steep for development to begin with.

"I'm not really sure what the outcome on all of this is going to be," she said.