Midewin National Tallgrass Prairie celebrates 25 years with time capsule

A call-to-action letter and seeds of a federally listed endangered leafy prairie clover were two of the items preserved in a time capsule on May 1 at Midewin National Tallgrass Prairie in Wilmington.

This Silver Anniversary time capsule will be sealed in the ground for the next 25 years. The letter was addressed to the USDA Forest Service staff in 2046.

Other items preserved in the capsule include lapel pins that represent organizations like the Midewin Interpretive Association and recognize “length-of-service of the hundreds of volunteers who have contributed to prairie restoration,” according to a news release from Midewin.

The capsule also includes a piece of clay from a farm irrigation tiles. These tales are currently being removed “to increase and improve habitat for chorus frogs and other wetland species,” the release said.

Digital photos, videos, and formative planning notes also went into the capsule, along with other items that provide a glimpse of life at Midewin during its first 25 years.

The time capsule installed where a farmhouse, the first USDA Forest Service building at Midewin National Tallgrass Prairie, once stood.

Midewin NTP Engineer Bob Hommes led the team that constructed a white concrete vault and 300-pound cap and enclosed the time capsule.

A white concrete vault and 300-pound cap was created from white silica sand, white aggregate, white Portland cement and water. This was mixed in small batches and shoveled into forms on March 19. The concrete was then allowed to set and cure.

Next, a four-feet-deep hole was created to protect the time capsule below the frost line. The lower portion of the vault was then set in the hole and then leveled and plumbed.

The hole was then backfilled with rushed concrete from an old WWII bunker to ensure the cap stayed level and upright. That bunker had been removed from the 811 bunker field in 2019.

Midewin NTP Engineer Bob Hommes led the team that constructed the vault and 300-pound cap. The team also enclosed the time capsule.

Once the time capsule was inside, Midewin NTP transportation assistant Esmerelda Suarez used a small crane and to lift the vault cap and set it in place.

The time capsule project was sponsored by the Midewin Tallgrass Prairie Alliance and the Midewin Heritage Association.