---

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D. C. 20549



---

FORM 10-K/A



---

(Mark One)

|x | ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | ------------------------------------------------------------------------------------

For the fiscal year ended December 31, 2005

OR



| ̈ | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | ----------------------------------------------------------------------------------------

Commission file number 1-12147



---

DELTIC TIMBER CORPORATION

(Exact
name of registrant as specified in its charter)



---



|                                                               |  |                                        
|-------------------------------------------------------------- |  | ---------------------------------------
|Delaware                                                       |  | 71-0795870                             
|(State or other jurisdiction of incorporation or organization) |  | (I.R.S. Employer Identification Number)



|                                                         |  |           
|-------------------------------------------------------- |  | ----------
|210 East Elm Street, P. O. Box 7200, El Dorado, Arkansas |  | 71731-7200
|(Address of principal executive offices)                 |  | (Zip Code)

Registrants telephone number, including area code: (870) 881-9400



---

Securities registered pursuant
to Section 12(b) of the Act:



|                                  |  |                                          
|--------------------------------- |  | -----------------------------------------
|Title of each class               |  | Name of each exchange on which
registered
|Common Stock, $.01 Par Value      |  | New York Stock Exchange, Inc.            
|                                  | 
|Series A Participating Cumulative |  | New York Stock Exchange, Inc.            
|Preferred Stock Purchase Rights   |  |                                          

Securities registered pursuant to Section 12(g) of the Act: None



---

Indicate by check mark if the registrant is a
well-known seasoned issuer, as defined in Rule 405 of the Securities Act    Yes ̈No  x.

Indicate by check mark if the registrant
is not required to file reports pursuant to Section 13 or 15(d) of the Act    Yes ̈No  x.

Indicate by check mark whether the registrant
(1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months, and (2) has been subject to such filing requirements for the past 90
days.    Yes  x    No ̈.

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein,
and will not be contained, to the best of registrants knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a
non-accelerated filer. See definition of accelerated filer and large accelerated filer in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer ̈Accelerated
filer    x        Non-accelerated filer ̈

Indicate by check mark if the registrant is a shell company (as defined in Rule 12b-2 of the
Act)    Yes ̈No  x.

The aggregate market value of the Common Stock held by non-affiliates of the registrant, based on the closing price of the Common Stock on the New York
Stock Exchange as of June 30, 2005, was $333,381,819. For purposes of this computation, all officers, directors, and 5% beneficial owners of the registrant (as indicated in Item 12) are deemed to be affiliates. Such determination should
not be deemed an admission that such directors, officers, or 5% beneficial owners are, in fact, affiliates of the registrant.

Number of shares of Common
Stock, $.01 Par Value, outstanding at January 31, 2006, was 12,343,661.

Documents incorporated by reference:

The Registrants definitive Proxy Statement relating to the Annual Meeting of Stockholders on April 27, 2006.



---