Exhibit 10.42

* THE COMPANY HAS REQUESTED AN ORDER FROM THE SECURITIES AND EXCHANGE COMMISSION
(THE “COMMISSION”) PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF
1934, AS AMENDED, GRANTING CONFIDENTIAL TREATMENT TO SELECTED PORTIONS.
ACCORDINGLY, THE CONFIDENTIAL PORTIONS HAVE BEEN OMITTED FROM THIS EXHIBIT, AND
HAVE BEEN FILED SEPARATELY WITH THE COMMISSION. OMITTED PORTIONS ARE INDICATED
BY “[REDACTED]”.

CONFIRMATION NO. 2

This Confirmation is attached and made part of that certain Master Crude
Purchase Agreement (the “Agreement”) by and among CountryMark Cooperative, LLP,
as purchaser (the “Purchaser”), and PennTex Resources Illinois, Inc, PennTex
Resources, LP, Rex Energy IV, LLC and Rex Energy I, LLC, as suppliers (each a
“Supplier”, and collectively, the “Suppliers”), dated December 30, 2009. This
Confirmation relates to the Crude to be sold to Purchaser pursuant to the
Agreement by each of the Suppliers. This Confirmation replaces all prior
Confirmations between Purchaser and each Supplier pursuant to the Agreement. Any
capitalized terms not defined herein shall have the meaning given them in the
Agreement.

 

1. Term: This Confirmation shall be for a period of twelve (12) months beginning
on January 1, 2011 and ending on December 31, 2011.

 

2. Quantity: An amount equal to actual lease receipts from trucked leases(s)
indicated on Exhibit “A” attached hereto and made a part hereof and/or
additional leases as designated by Suppliers. Leases can be added or deleted
from Exhibit “A” during the term of this Confirmation as agreed by Purchaser and
Suppliers.

 

3. Delivery Points(s): Delivery shall take place and title shall pass from each
Supplier to Purchaser when the Crude comes under the physical control of
Purchaser by passing from the well tankage located on the leases to Purchaser’s
designated transportation vehicles.

 

4. Crude Price: For the Crude sold and delivered hereunder, Purchaser agrees to
pay a price per barrel, which shall be calculated as follows:

[REDACTED]*

[REDACTED]*

 

5. Payment Account: Purchaser shall make all payments pursuant to this
Confirmation to each of the Suppliers by wire transfer to the following
accounts:

 

Rex Energy I, LLC    PennTex Resources Illinois, Inc.    Bank: M & T Bank   
Bank: M & T Bank    ABA: 022000046    ABA: 022000046    Acct: [REDACTED]*   
Acct: [REDACTED]*    Rex Energy IV, LLC    PennTex Resources, LP    Bank: Key
Bank    Bank: M&T Bank    ABA: 041001039    ABA: 022000046    Acct: [REDACTED]*
   Acct: [REDACTED]*   

--------------------------------------------------------------------------------

       Suppliers:    Purchaser:     PENNTEX RESOURCES ILLINOIS, INC.   
COUNTRYMARK COOPERATIVE, LLP     By: /s/ THOMAS STABLEY    By: /s/ BILL COLLINS
Name: Thomas Stabley    Name: Bill Collins Title: Executive Vice President and
Chief    Title: Senior Crude Oil Representative Financial Officer         
PENNTEX RESOURCES, LP          By: /s/ THOMAS STABLEY      Name: Thomas Stabley
     Title: Executive Vice President and Chief      Financial Officer         
REX ENERGY IV, LLC          By: /s/ THOMAS STABLEY      Name: Thomas Stabley   
  Title: Executive Vice President and Chief      Financial Officer          REX
ENERGY I, LLC          By: /s/ THOMAS STABLEY      Name: Thomas Stabley     
Title: Executive Vice President and Chief      Financial Officer