OF Cawley, Gillespie & Associates, Inc.
acknowledge that the results of our independent reserve estimates for Carbon Natural Gas Company (the “Company”),
with an effective date of December 31, 2015 and a preparation date of February 24, 2016, are reported in the Company’s annual
report on Form 10-K for the year ended December 31, 2015. We hereby consent to the results of our independent reserve estimates
for the Company from our report dated February 24, 2016 being included in the Form 10-K and each Company registration statement
that may be filed hereafter. We further consent to the use of our name in the section of the Form 10-K entitled “Preparation
of Reserves Estimates” and any reference to our firm or employees as “Experts”.
Cawley, Gillespie & Associates, Inc.
Zane Meekins, P. Eng.
Gillespie & Associates, Inc.