How an Oil Spill Tainted a Pristine Forest

Whether you’re headed toward Gaylord for a winter weekend, chasing snow at Treetops, or simply looking for a stretch of sky that feels larger than the noise below, the appeal is the same: This part of the state still feels untouched.

That feeling makes what happened in April 2025 harder to process.

One of Michigan’s largest recent oil and gas releases did not occur near a refinery, highway interchange, or industrial corridor. It occurred in wetlands within the Pigeon River Country State Forest—an area often referred to as “the Big Wild.”

The initial estimate of the release was 50 barrels. It was later revised to 220.

What happened between those figures—and what continues to happen at the site—is a more complicated story about aging infrastructure, regulatory response, and the long road from contamination to restoration.

The spill was reported on April 16, 2025, through Michigan’s Pollution Emergency Alerting System. By the time the operator made the call, daylight was gone. The surrounding forest had recently been torn up by a severe ice storm.

Access was limited. Visual assessment was difficult.

Michael Shelton, a senior geologist with the Michigan Department of Environment, Great Lakes, and Energy (EGLE), arrived at the site the following morning. The original estimate—50 barrels—was based on what could be observed in darkness under chaotic conditions.

“They were just trying to go off of visual indicators of what they saw,” Shelton said.

Once daylight revealed the extent of surface staining and pooling, Shelton suspected the volume was higher.

“It looked a little bit too big to be just 50 barrels,” Shelton said.

In the days that followed, EGLE and the operator conducted interviews, reviewed records, and calculated flow data. By April 25, a revised estimate had been determined: 220 barrels total—approximately 100 barrels of condensate, 110 barrels of brine, and 10 barrels of crude oil.

Public confusion arose months later when that revised number appeared in a December update on the state’s incident webpage. Early descriptions of the release referred to crude oil, but that description was incomplete.

The flowline involved carried a mixture of crude oil, brine, natural gas, and condensate—substances produced together from underground formations before being separated at a processing facility. In this case, there was more brine than crude.

Brine is often described simply as saltwater, but it is saltwater produced alongside hydrocarbons. It contains elevated chloride concentrations and can carry petroleum-related compounds.

Shelton said these are commonly known as BTEX chemicals—benzene, toluene, ethylbenzene, and xylenes—which are regulated because of their potential health impacts.

Understanding exactly what moved through the line mattered. Cleanup standards differ depending on contaminant type. Without identifying the composition, regulators cannot apply the appropriate thresholds.

According to Shelton, the release occurred during a routine maintenance operation known as pigging. Pigging involves sending a cleaning tool through a flowline to remove sediment or paraffin buildup.

In this case, the pig tool became lodged in the approximately 50-year-old line. Pressure was applied in an attempt to move it forward. A weld failed. The rupture allowed the mixture inside the line to escape into the surrounding wetland.

“It didn’t have to be this big of a release,” Shelton said.

The spill emerged from the ground. Petroleum fluids bubbled up before flowing along a visible path toward a conifer wetland. The impact above ground was immediately apparent. What happened underground required investigation.

Shelton described finding wetland contaminants as a three-dimensional system involving soils above and below ground, groundwater, and even air pathways. Field crews used photoionization detectors to identify hydrocarbons and conductivity meters to trace chloride migration associated with brine.

Soil borings and monitoring wells were installed to assess subsurface movement. Samples were sent to independent laboratories for analysis and compared against established state criteria. The complete extent of the environmental impact hasn’t been determined yet.

Monitoring has identified detections in nearby tributary creeks, though concentrations have not exceeded toxicity thresholds. Recent sampling sessions have shown declining levels, but it is too early to establish a long-term trend. Regulators have not identified a pathway to residential drinking water wells, nor evidence it got to Canada Creek or the Black River.

The site remains active.

“This one’s going to be a multi-year project,” Shelton said.

The timing of the release shaped its trajectory. Sub-freezing temperatures in mid-April thickened crude oil and condensate, limiting their mobility. The crude “gelled up,” reducing lateral spread. If the rupture had occurred during warmer summer conditions, Shelton believes the area of impact would likely have been larger. Brine, however, did not freeze and continued moving through the wetland system.

Frozen ground both hindered and helped the response. Equipment malfunctioned in the cold. Vacuum truck lines froze. Crews worked in difficult conditions. At the same time, the frozen wetland allowed temporary access roads to be constructed, reducing additional disturbance from heavy equipment.

The location itself presents challenges that urban sites do not. There were no established roads leading directly to the affected corridor. Crews built temporary access routes and installed a check dam to limit further migration of contaminants. Some brine had already moved beyond that barrier before completion, and regulators continue monitoring nearby tributaries.

Cleanup standards do not change based on geography. Michigan’s contaminant thresholds apply whether a spill occurs in a city or a forest.

What changes are the exposure pathways. In urban areas, regulators must consider vapor intrusion into basements and immediate proximity to residents. In the Pigeon River Country State Forest, human exposure pathways are limited. Ecological considerations dominate.

The flowline involved was installed roughly five decades ago. Much of Michigan’s oil and gas infrastructure predates modern environmental standards and the land-use expectations that followed.

When failures occur in remote landscapes, they can pass without spectacle. There are no dramatic shoreline slicks or burning facilities. Instead, there is excavation in cold forests, monitoring wells in wetlands, and years of testing to confirm that contaminants are receding.

The 220-barrel figure may have drawn attention. The more enduring story is what follows: long-term remediation, continued monitoring, and the slow work of restoring a wetland that took generations to form.

Northern Michigan often feels untouched. The Pigeon River spill is a reminder that infrastructure and wilderness sometimes share the same ground—and when something fails beneath the surface, repairing that breach takes a lot of time.