Cleanup and assessment efforts continue in Montana after a July 1 pipeline rupture that sent crude oil gushing into the Yellowstone River. On Tuesday, Montana’s environmental agency said that oil was found on 60 percent of the inspected shoreline. The state also said that the spill released 1,200 barrels into the river, up from Silvertip pipeline operator ExxonMobil’s estimate of 1,000 barrels. The company has completed initial cleanup work on four of the 25 identified spill sites, according to the EPA.

The effects of the rupture are trickling beyond the spill region: It is being cited by opponents of plans to expand TransCanada’s controversial Keystone XL oil pipeline.

“We write to express our continuing concerns regarding TransCanada’s