Trinity Cemetery lies about a mile and a quarter south-west of Foster, in Pierce County, Nebraska. It is a small country burial ground with only two burials indexed.
It is easily missed. The Pierce County cemetery index does not list it at all — it appears only on Find a Grave, filed under Foster. Its recorded position agrees with Find a Grave's own stated distances to its neighbors to within a tenth of a mile in every case: 3.6 miles from Stark Valley Lutheran, 3.9 from Lambrecht, 6.1 from Dedlow-Zion and 6.7 from Walker Family.
Take care with the name. Boyd County has a Trinity Lutheran Cemetery at Bristow, and there is an Evangelical Lutheran Trinity Cemetery down in Seward County; neither is this one.
Find a Grave holds 2 memorials for it, which is a record of what has been photographed and indexed rather than a count of everyone buried there. For burial records or plot inquiries, contact the Village of Foster, or the Pierce County Clerk in Pierce. Ownership can also be confirmed through the Nebraska Statewide Cemetery Registry at the State Historical Society.