The following Metaculus forecast will open soon:

https://www.metaculus.com/questions/14441/3-us-lithium-mines-before-2030/

This question asks whether at least three lithium mines will operate in the US at any time before the start of 2030. Currently there is one active Lithium mine in the US with some more planned. See the link for detailed resolution criteria.

When the Metaculus question opens, this Manifold market will close and seven days later resolve PROB to the Metaculus "Community Prediction." This procedure is known as Reciprocal Scoring. Since Manifold incentivizes betting to the correct expected value, this is a proper scoring rule assuming Metaculus, which has a solid track record of good forecasts, is an unbiased estimator.