"They built that dam in 1939, and what it's drained to now is what it was then," Jessop said. "It's not very pretty, but it's really interesting to see what it was back then."
For Logan resident Sonny Mason, the sight of Tony Grove Lake was a surprise - even though he had heard about the project. Mason and a friend rode up on their motorcycles "out of curiosity." His childhood memories of playing in the lake didn't match what he found last week.
"It is pretty low, and pretty nasty looking," Mason said. "It will be nice when they get it done."
Cache Forest spokeswoman Lisa Perez said the dam will be reinforced to bring the structure into compliance with state Department of Natural Resources, and state Division of Water Rights requirements.
Inspections found structural inadequacies that could affect public safety, including the potential to flood the Lewis M. Turner Campground should a seismic event occur, she said.
"We are not rebuilding it," Perez said. "We are just re-stabilizing it and bringing it up to code."
Construction, initially scheduled to begin this month and end in November, already is behind schedule. Officials reopened the bid after only one contractor responded earlier this summer, Jessop said, and the second round of advertisements for the job found several interested contractors on site last week to tour the dam.
Once the crew has been selected, construction is expected to begin immediately and conclude in about 90 days, according to Mike Van Horn, recreation technician for the Logan Ranger District.
Then the lake, currently about 9 surface acres, will be restored to its typical size, roughly 26 acres, by the natural stream that feeds it.
Meanwhile, visitors evaporated as rapidly as the water, according to Jessop.
Fishing, canoeing, and other aquatic activities will be restricted.
Parking and road travel might also be congested due to construction.
For the determined recreationist, though, he said, Tony Grove still offers ample hiking trails, wildlife sightings and even fishing.
"I put 3,500 fish in there this year. It's still about 40 feet deep out there. There's a lot of fish still left, but it's kind of hard to get to them."