The fire tower from which a fit, vibrant and independent 70-year-old woman mysteriously disappeared two years ago rises above the lush mountain forest of northwestern Alberta like a question mark.

Where is Stephanie Stewart and what happened to her?

The mystery continues to haunt her family, the RCMP and members of the volunteer Hinton Search and Rescue Association. But they all hold out hope of finding answers to a case that police are treating as a homicide.

"As I talk to you right now, on my deck, I can see the tower. It is pretty near and dear to me," said Marc Symbaluk, president of the search and rescue association, whose volunteers have spent countless hours combing the woods for evidence.

Symbaluk managed the first search for Stewart when she was reported missing. The team, which works closely with the RCMP, has gone back to the area time after time since to look for clues.

"Two years haven't faded my desire to seek some closure to this."

Stewart, a former bookstore owner who loved nature and the solitude her lonely job offered, was last heard from on Aug. 25, 2006.

The following morning she was reported missing when she failed to check in as part of her normal duties as a fire tower worker — a job she had performed for 18 years.

A pot of water was left boiling on the stove. Police suggest that means she was interrupted during her morning routine.

An RCMP major crimes unit continues to investigate. A $20,000 reward offered by the Alberta government and the Alberta Union of Provincial Employees has gone unclaimed.

This spring, Mounties again distributed posters of Stewart in the Hinton-Jasper area that include her picture and a description of several items that were also missing from the fire tower: two pillows with blue pillow covers, a burgundy bed sheet, a Navajo-patterned duvet and a gold watch.

While it's not much to go on, police hope someone, somewhere, will come forward with information that will help crack the case.

Craig Albers, an RCMP spokesman, said it could be something as seemingly innocuous as a piece of clothing found by a trail. The Mounties have also written to people who have camped in the area in the hope of jogging someone's memory.

"All tips are very actively pursued. Sometimes people find information that they might not think is pertinent," Albers said. "It is better to give us that information and let us decide than to shrug it off.

"Obviously, somebody knows something about this."

Stewart's family has remained silent about her disappearance, making only one public statement two years ago, but RCMP officers speak with Stewart's relatives at least a few times each month.

Stewart's disappearance prompted the Alberta government to review safety at its network of 128 lookout towers that stand like sentinels throughout the province's forests. A report with recommendations was released last summer and the government continues to make improvements. 

Each of the 80 drive-to fire lookouts now have gates that restrict access to them. Other measures include equipping all lookout staff with hand-held radios that have a panic button in case of trouble. 

There is also a new training program that all staff, including veterans, must complete, said Mike Jenkinson, a spokesman for the Sustainable Resource Development Department. 

Stewart has not been forgotten, he said.

"Two years later, I can tell you that this still hurts, and there are people in this department for whom this is still an open wound. 

"They miss her, and they would like to see some resolution to this."