Texas independent Enduro Resource Partners LLC, founded by Jon Brumley and his son Jonny, has filed for Chapter 11 bankruptcy protection and is preparing to sell its assets in six states.

The Fort Worth-based company, formed in 2010 with about $200 million from Riverstone Holdings LLC, has been “undermined by persistently low oil and gas prices during the past several years,” CFO Kimberly Weimer said in the court filings with the U.S. Bankruptcy Court for the District of Delaware. Debt “became insurmountable,” the filing indicated.

Enduro has leaseholds in Louisiana, Montana, New Mexico, North Dakota, Texas and Wyoming. In 2016 it sunk $26 million into the company but it was unable to restructure the debt, the filings indicated. It also was unable to meet a deadline of March 30 to pay $208.7 million owed. It also has debts of more than $141 million with one trust, as well as owing nearly $4 million to its top 30 creditors.

Enduro executives “did not anticipate in the early part of this decade that they would eventually succumb to the demands of repaying the capital they borrowed to invest in their exploration and production activities,” Weimer’s filing said.

As it sheds assets, Enduro plans to continue operate its subsidiaries and affiliates.

Last September it sold some of its oil and gas properties in the Permian Basin for $49 million. It now has properties divided into four packages and said it has secured stalking horse bids for three, which altogether could provide almost $97 million, according to court documents.

An auction to test support for other bids is set for July 19.

Most of Enduro’s 70 member staff are in Fort Worth (42), and bonuses totaling $1.5 million have been offered to about 35 employees to remain through the bankruptcy proceedings.

In 2010, the Brumleys sold Encore Acquisition Co., which they founded in 1998, to Denbury Resources Inc.in a deal valued at $4.5 billion. The elder Brumley previously was CEO of Southland Royalty Co. He also co-founded Cross Timbers Oil, which became XTO Energy Inc., now a subsidiary of ExxonMobil Corp. In addition, he previously was CEO of Mesa Inc., once headed by the legendary T. Boone Pickens.

Enduro has retained Latham & Watkins LLP and Young Conaway Stargatt & Taylor LLP as co-counsel, Evercore Group LLC as financial adviser and Alvarez & Marsal North America LLC as restructuring adviser.