A little more than an hour's drive from Spokane, a Seven Bays, Wash.-based company owned by a Spokane couple offers cabin rentals with access to hundreds of miles of waterfront.

The cabins are really luxury houseboats and the company, Dakota Columbia Rentals LLC, has eight of them, each of which are worth well over $300,000. The 16-foot wide boats are available in two sizes—60 feet long and 62 feet long. The waterfront is the shoreline of Lake Roosevelt.

Each boat is a mobile vacation lodge that sleeps up to 14 and can go just about anywhere on Lake Roosevelt, says Laurel Parker, who heads up Dakota Columbia. Parker and her husband, Lyle, a recently retired Alaska Airlines pilot, own the company. They live in Seven Bays during the summer months. Their son, Mike, and daughter-in-law, Andrea, also help run the operation, and the company employs 10 other people. The houseboats come stocked with most amenities vacationers need, ranging from filled fuel tanks to acrylic wine glasses, Parker says.

"All you have to do is pack up sleeping bags, pillows, and food," she says.

Dakota Columbia's boats are moored at 7 Bays Marina in the lakeside community of Seven Bays, about 65 miles east of Spokane. The company also operates the marina, and soon will take over operations at the Keller Ferry Marina, also on Lake Roosevelt.

Parker declines to disclose Dakota Columbia's revenues, but says they had been steady and growing up until last year, when the business experienced a modest decline. Judging by reservations for the coming season, it appears revenues will recover this year, she says.

Lake Roosevelt is a 150-mile stretch of the Columbia River impounded by Grand Coulee Dam, which was completed in 1942. The lake has 660 miles of shoreline and is a national recreation area managed cooperatively by the National Park Service, Bureau of Reclamation, Bureau of Indian Affairs, the Spokane Tribe of Indians, and the Confederated Tribes of the Colville Reservation.

Each boat has a large enclosed living area that includes a state-of-the art home-theater system with satellite TV, a fully equipped kitchen, and staterooms in a split-level compartment. A doorway near the stern opens to a small deck with an outside shower, and a stairway leads from there to the larger sundeck with lots of seating and an eight-person hot tub.

Each boat has a 140-horsepower, inboard-outboard motor and a cruising speed of 8 to 10 knots. The boats have two 120-gallon fuel tanks, one of which is a mobile gas station for fueling personal watercraft or ski boats that customers bring with them.

Dakota Columbia provides new customers with a training session, which includes practice at beaching the boat, Parker says.

A few customers cruise the entire length of the lake, but most find a secluded beach and don't go very far from there, she says.

"You could just go across the lake and not spend much gas at all. You can pull up on any beach. There are no private docks on the lake," Parker says.

She puts journals on houseboats, "and some people just love to write," she says.

Journal entries have included sightings of moose, otters, mountain lions, and wild turkeys that have thrilled vacationers, Parker says. "You never know what you're going to see," she says.

Dakota Columbia entered its houseboat-rental market with three sparsely furnished boats about 20 years ago, but upgraded the floating stock to luxury houseboats starting in 2000, because customers requested more features such as hot tubs and TVs.

The company's houseboats are made by Twin Anchor Marine, a custom boat manufacturer in Sicamous, British Columbia, on Lake Shuswap, about 112 miles north of Seven Bays.

Before the company selected Twin Anchors as its manufacturer, the Parkers traveled around North America with their own design criteria, Parker says.

"We brought ideas we had to Twin Anchor, and they incorporated them in their designs," she says.

Seven Bays is Dakota Columbia's third location on Lake Roosevelt since the Parkers incorporated the company in 1991.

Parker says she was looking for business opportunities in the late 1980s, when she first vacationed on Lake Roosevelt.

"We were kicking a lot of ideas around when we rented a houseboat at Kettle Falls with our two boys and my sisters and their families," she says.

During that vacation, she started to develop her own vision for a houseboat-rental venture.

"We came back and talked to the marina operator," Parker says. "He was interested in us buying the boats, and he would operate them for us."

Five years later, Dakota Columbia's fleet had grown to five boats and Parker moved the operation 60 miles south on Lake Roosevelt to the Spokane Tribe's Two Rivers Casino & Resort Marina, near the mouth of the Spokane River, Parker says. The company worked with the tribe for 10 years as the tribe developed its own houseboat-rental business, which currently includes three boats based at the Two Rivers marina, she says.

In 2006, the Park Service asked Parker to take over the marina-concession contract at Seven Bays, a community about seven miles south of Two Rivers, and Dakota Columbia moved there, Parker says. That concession formerly was held by the Colville Tribe, which opted out of the marina and houseboat operations there, she says.

"The Park Service liked the way we ran our operation," Parker says. "They wanted to have houseboats there."

As the new operator there, she tweaked the name to 7 Bays Marina.

The marina includes 150 slips and a convenience store with an attached restaurant. Parker renamed the 75-seat restaurant Blue Coyote Grille and expanded the store's inventory to include gift items, boating-related products, and camping gear.

The Park Service ultimately oversees the operations and sets pricing guidelines for food, fuel, moorage, and houseboat rentals, and Dakota Columbia pays the service a percentage of its gross receipts for the concession, Parker says. The Park Service recently extended the 7 Bays concession for two years under a temporary contract and then will put it out to bid for a 10-year contract, she says.

"Anything we do to improve the property has to be approved," Parker says.

Parker and the Park Service also are completing negotiations for a two-year contract with Dakota Columbia to take over the Keller Ferry Marina concession, which the Colville Tribe also ran until April. Keller Ferry Marina includes about 110 boat slips and a convenience store.

"The Park Service wants to keep moorage, gas, and a (sewage) pump-out station there," she says.

Dakota Columbia likely won't base houseboats at Keller Ferry unless it pursues and wins a longer-term contract there, she says.

The company's prices for seven-day houseboat rentals range from $4,400 early and late in the season to $7,500 in the peak of the season. Dakota Columbia also offers three- and four-day rentals that range in price, respectively, from $3,000 to $4,400 and from $3,300 to $4,700. The boats come with full fuel tanks and customers pay for the fuel that they use when the tanks are refilled upon their return, Parker says.

Boats typically are rented by multiple families or couples who share the cost, Parker says.

Most of the week-long vacationers come from West Coast cities or from farther away. Customers from closer locations are more likely to rent for shorter periods, she says. "A lot of Spokane or Tri-Cities people just want to go out for the weekend," she says.

The full season runs from late May to late September.

In response to requests for houseboat rentals for smaller groups, the company is drawing up plans for 35-by-10-foot boats, which customers could buy and lease back to Dakota Columbia. The company then would rent the smaller boats out when the owners aren't using them, Parker says.

"A few people are interested in investing in them, and we're putting together a presentation to give to them," she says.

Parker says the business keeps her too busy to boat for most of the summer, although she likes to take time to enjoy the lake with friends and family in September.