Credit: Waukesha County Sheriff's Department/Facebook

A Wisconsin teenager's mysterious disappearance is frustrating local investigators, who say they have recovered the missing girl's bicycle, but have developed no significant leads to push the investigation forward.

Kathryn Stalbaum, 15, of Genesee, Wis., was last seen on her way to school Tuesday morning after missing her school bus. She texted a friend that she would ride her bike to Kettle Moraine High School instead.

But Stalbaum never arrived, prompting school officials to alert the girl's parents who then reported her missing to the police.

Authorities recovered the teal-colored bike belonging to Stalbaum Thursday near Waukesha Memorial Hospital, and plan to pay special attention to the city of Waukesha in their efforts to locate the teen.

"We do not have a lot of good reliable leads," Inspector Eric Severson of the Waukesha County Sheriff's Department announced at a press conference Friday. He said the Sheriff's Department was unsure how the bicycle wound up near the hospital.

"There is equal reason to believe Kathryn brought the bicycle to Waukesha as there is to believe she didn't," Severson said.

Severson says the Stalbaum family, which has requested privacy at this time, is coping the best they can.

"They are coping in my opinion, heroically," Severson said. "They are hopeful and we are hopeful."

Police are reviewing surveillance video from cameras located near Waukesha Memorial Hospital and asking businesses that have surveillance cameras to review their video for any potential footage of Stalbaum.

A $1000 reward is being offered for information relating to Stalbaum's disappearance. Investigators are urging the public to download Stalbaum's picture to their phones from the Waukesha County Sheriff's Department's Facebook page. She is 5'7?, with long brown hair, blue eyes, and braces. She was last seen wearing a sweatshirt and pink Nike Tennis shoes.