Petroleum County, MT Water Table Trend
The nearest real water-table reading to Petroleum County, MT
The closest qualifying well to Petroleum County is 83 miles away in Yellowstone County, MT, where the trend runs declining at a typical pace for a declining county.
Petroleum County itself has no monitoring well with enough history to call its own trend, so treat this as a regional estimate, not Petroleum County's own number. If you own a well here, comparing your own depth log against this regional figure is worth doing before assuming either way. See Yellowstone County, MT's full page. See the no-data guide for why a county this close to a qualifying well still doesn't get its own number.
Petroleum County, Montana in brief
About 525 people live across Petroleum County's 1,656 square miles, in Montana. USGS's National Groundwater Monitoring Network covers 1,449 of 3,222 US counties (45%) today; Petroleum County isn't one of them yet, see the methodology guide for the exact qualifying bar.