Searchers are keeping up their mission to find two canoeists from southern Minnesota who have been missing for more than a week in northwestern Wisconsin, officials said Monday.

The Douglas County (Wis.) Sheriff's Office was alerted about a canoe capsizing sometime during the last weekend of October on the Minong Flowage in Wascott, officials said.

Efforts to locate Ryan J. Busch, 26, and Andrew T. DeRock, 27, both from New Ulm, "began almost immediately" and involved personnel from the Wisconsin Department of Natural Resources, the Sheriff's Office and numerous fire departments and search-and-rescue units.

What began as a rescue mission shifted last week to an effort to find the pair's bodies.

"The recovery operation continues, [and] deputies have been on scene every day since the incident along with several other assisting agencies," Sheriff Matt Izzard told the Star Tribune. "There is no timeline for discontinuing. Ice on the lake will determine the timeline and length of the search."

Obstacles such as weather, cold water temperatures and natural foliage in the search area have hindered recovery efforts, the statement continued.

Organizers of an online fundraising campaign on behalf of both families said in a posting that the men's families have been helping with the search in northern Wisconsin since Oct. 29.