JEROMESVILLE — Sparse leaves on outstretched branches provide scant shade for the tall grass below. Sunlight beams down through patches of spotty green like a kaleidoscope.

About 50 feet away, a tributary of the Jerome Fork of the Mohican River slowly winds through farmland, separating the tree from adjacent fields of crops. Birdsong provides nature’s background music.

Large, bulbous burls on this wilderness sentinel cover scars of trauma, adorning the trunk. The gnarled trunk of this massive American Sycamore, which is at least two centuries old, measures 436 inches in circumference, and the tree stands 88 feet tall. A portion of the trunk is hollow — a cavity measuring more than 8 feet tall.

“These big trees, you don’t see a whole lot of them. So when you do, you really appreciate them. You want to document them,” said Alistair Reynolds, a forester for Ohio Department of Natural Resources who coordinates the Ohio Big Tree Program. “There’s also a scientific component here, too. We try to maintain a database of the largest trees.”

The program tracks the largest trees in the state by species and uses measurements of the tree’s crown spread, its height and circumference to assign each tree a score. Reynolds visits trees nominated by the public, and he uses a tape measure, laser rangefinder/hypsometer, which measures height, and a Light Detection and Ranging (LIDAR) device, which uses light via a pulsed laser to take other measurements.

Other states have similar programs. American Forests, a nonprofit group dedicated to reforestation, has a list of “champion” trees across the country, and uses the data to declare national record holders. Researchers can look at the numbers kept by states to determine how large some species of trees will grow.

This tree has four major stems, like secondary trunks, forking up from the main trunk, although only three are counted when it comes to competitions against other trees because one stem is below a 4 1/2-foot minimum height mark used in judging. (That means some judges would consider one of the stems a separate tree.) Smaller offshoots have branched off the massive trunk but now have dropped leaves. The total score of the tree is 547 — making it the largest tree on record in the state.

The tree is now in the process of dying. It is believed to be hundreds of years old, but there is no way to know exactly how old it is — especially with the hollow trunk. Reynolds estimates that because of its size, it easily pre-dates Ohio’s statehood in 1803.

It’s also the largest American Sycamore in the country.

“Not only is it the biggest tree, it’s probably the hollowest tree,” in Ohio, Reynolds said.

Anthracnose fungus has caused witches broom patterns on twigs and healthy leaves to be scarce. A fungus also left the gaping hole in the trunk.

“If the rate of decay exceeds the growth rate, then it’s going to have some challenges,” he said. “As high as the rot grows up the stem, it’s likely to fail.”

In this program, “one good storm can change everything,” Reynolds said. Last week’s storms tore down the state’s champion white oak tree in Canfield in Mahoning County in northeastern Ohio that had a full picturesque canopy.

Even as the tree’s health fails, there’s something majestic about its presence. Those on the big-tree list impart a sense of serenity to people who get up close.

“They are inspiring. You get a really cool feeling when you’re around a big tree versus hanging out around one of those maples,” Reynolds said standing in a corn field and gesturing over to a smaller group of trees. “You don’t really feel anything around those. But when you get around a monster tree, you definitely feel — I feel — a connection around them.”

Marc DeWerth is the founder of Big Trees Ohio, a group of conservationists with a Facebook page on which members post photos of large trees and often include measurements. DeWerth routinely follows up on tips submitted on the page and holds contests challenging the group to find even larger trees. The next contest, beginning June 2, will be a search for the largest undocumented American Sycamore.

“It won’t beat this one unless it’s a multi (stem). But I’m positive. There’s so many big ones in our state. They are hidden on the rivers,” DeWerth said.

A small plaque is posted near base of the Ashland County tree reading, “Nation’s Largest Sycamore,” and dates back to 1970 when it was first recognized by American Forests. It displays the name of the former landowner who passed away at the age of 90 last year. He would host occasional tours to show off the tree. His family still owns the land.

Reynolds plans to return to the tree in the coming weeks to inspect its foliage and general health.

DeWerth recently assisted Reynolds with measurements.

“Just imagine all the stories that tree can tell us after its long ... life,” DeWerth said. “Plus, the fact that it has seed(ed) other sycamores in that area will ensure that species’ survival ... for many years to come.”

Anyone interested in submitting nominations for big trees across the state of Ohio can visit forestry.ohiodnr.gov/bigtree or contact Reynolds at alistair.reynolds@dnr.state.oh.us.