Exhibit 24.2
POWER OF ATTORNEY
KNOW ALL MEN BY THESE PRESENTS that Peter Wehrly hereby appoints Larry Jasinski and Kevin Hershberger, and each of them, his true and lawful attorneys-in-fact and agents, with full power to act separately and full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to the registration statement on Form S-3 (File No. 333-209833) and any additional registration statements related thereto pursuant to Rule 462(b) of the Securities Act of 1933, as amended, and to file the same, with all exhibits thereto, and all other documents in connection therewith, with the SEC, granting unto each said attorney-in-fact and agent full power and authority to do and perform each and every act in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or either of them or his or her or their substitute or substitutes may lawfully do or cause to be done by virtue hereof.
PETER WEHRLY
/s/ Peter Wehrly
Director
Date: May 5, 2016
