SecProbe.io

July 21, 2015

Via E -Mail
Mr. Ryan Ellson
Chief Financial Officer
Gran Tierra Energy Inc.
200, 150 13th Avenue S.W.
Calgary, Alberta
Canada T2R 0V2

Re: Gran Tierra Energy Inc.
 Form 10-K for the Fiscal Year Ended December 31, 2014
Filed March 2, 2015
Response Letter dated June 16, 2015
File No. 001 -34018

Dear Mr. Ellson :

We have reviewed  your June 16, 2015 response to our comment  letter  and have the
following comment s.  In some of our comments, we may ask you to provide us with information
so we may better understand your disclosure.

Please respond to these comments within ten business days by providing the requested
information or advise us as soon as possible when you will respond.  If you  do not believe our
comments apply to your facts and circumstances, please tell us why in your response.

After reviewing your response to these comments, we may have additional comments.
Unless we note otherwise, our references  to prior comments are to comments in our  June 4, 2015
letter.

1. We have read your response to prior comment one, indicating several reasons why you
have not quantified the reasonably possible effects of lower commodity prices on your
development plan s and accounting under the full cost methodology.   For example, we
note the following remarks.

 You explain that upon filing your annual and subsequent interim report you
“believed that it was possible that development capital would not be permanently
deferred to 2016 or beyond”;

 you express the views that “statements quantifying possible future ceiling test
impairments based upon estimates are potentially misleading” and “providing

Mr. Ryan Ellson
Gran Tierra Energy Inc.
July 21, 2015
Page 2

 impairment sensitivity based on changes in commodity prices changes al one
would be misleading”; and

 you state that you do not believe the several months of depressed oil prices at the
time of filing your reports “represent a long term permanent decline in oil
prices.”

The requirements to address trends and uncertainties  and their reasonably possible effects
in Items 303(a)(1), (2)(ii), and (3)(ii) of Regulation S -K, as well as Instruction 3 to that
guidance, do not depend on certainty or permanence as conditions for disclosure, as
suggested in your reply.   Rather, the re quirements apply to the reasonably possible
material impacts of known trends or uncertainties.

You disclose on page 55 that you recently changed your business strategy “Largely as a
result of the current low commodity price environment” and, with regard to the Bretaña
field, reclassified as contingent resources all probable and possible reserves associated
with the field and recognized a related impairment charge of $265 million.   You state
“Sustained periods of low oil prices could be detrimental to our financial performance.”

Given the foregoing and your response, it appears that it is at least reasonably possible
that the impact of lower prices will be material.  On a related point, your statement that
there is a possibility that development capital has  not been permanently deferred seems to
imply that development capital has been deferred for an indefinite period, and may
depend on an uncertain increase in c ommodity prices in the future.

SEC Release 33 -8350 clarifies that quantified disclosure regardin g the material effects of
known material trends and uncertainties should be provided if quantitative information is
reasonably available.  In view of this, and given your disclosure regarding possible future
impacts on development plans, we believe that yo u should expand your disclosure to
quantify the impact on proved reserves if assumed price increases do not occur .

Separately, given that you would ordinarily have nine or ten of the twelve prices needed
for the next ceiling test at the time of filing you r periodic reports, we also believe that you
should disclose information about the magnitude of any material reasonably possible
upcoming ceiling test write -downs, based on information known to you in advance of
filing your report, along with any of the un derlying assumptions that are necessary to
clarify the nature of this disclosure.

Mr. Ryan Ellson
Gran Tierra Energy Inc.
July 21, 2015
Page 3

 You may contact Joseph Klinko at (202) 551 -3824 or Kimberly L. Calder at (202) 551 -
3701 if you have questions regarding comments on the financial statements and related  matters.
Please contact me at (202) 551 -3489 with any other questions .

Sincerely,

 /s/ Brad Skinner

Brad Skinner
Assistant Chief Accountant