As students have come and gone, and buildings too, these towering trees have remained an integral part of campus.
The university is in the process of identifying the oldest trees on campus as it celebrates its centennial in 2010.
"We didn't think it would be right to celebrate our 100th anniversary without acknowledging the only living things on campus that are as old as the university," BGSU spokesman Dave Kielmeyer said.
BGSU plans to put together a Web site with a walking tour or put markers at each century-old tree as part of the celebration of the university's founding in 1910.
Mr. Kielmeyer came up with the idea for the project and got Helen Michaels, a BGSU associate professor of biology, and Frank Schemenauer, university horticulturalist, to help.
The university officials, along with Stephanie Miller, regional urban forester for the Ohio Department of Natural Resources' forestry division, recently took short core samples from a number of the older trees to age them.
Results are not yet available, but it is believed there are more than a dozen trees that have been around for more than 100 years.
The search began with archive photos to see what trees were on campus years ago and checking to see if they are still there.
A good portion of the historic trees were located using old aerial photos and ones of University Hall and its turnaround road lined with trees.
"We're fortunate to have some old photographs of campus, so we were able to home in on groups of trees that were probably there," Ms. Miller said. "They weren't mature trees yet by the time campus was built, but they were still sizable enough to be significant pieces of landscape."
Back when BGSU was founded as a twin "normal school" with Kent State University, part of the campus area was a city park and much of it was farmland, Mr. Kielmeyer said. The Oak Grove Cemetery was already located there.
The oldest trees have been found in the area known as inner campus near University Hall.
The largest tree identified was a white oak with a 42-inch diameter, but all of the older trees measured at least 30 inches, Ms. Miller said.
The project has been particularly interesting for Mr. Schemenauer, who was a groundskeeper and tree trimmer when he arrived on campus 20 years ago.
"I have been in a few of these trees climbing and trimming. I've spent a little time with a few of them,' he said. "I always knew they were the oldest and most mature trees on campus, and it will be neat to see how old they are."
Mr. Schemenauer said he hopes the project will help people appreciate the campus trees more.
"There's a core group of these trees that I would hope the rest of campus feels they are special as I do," he said. "They are very majestic and preside over the whole area up there."