SecProbe.io

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
CF/AD5
100 F STREET, NE
WASHINGTON, D.C. 20549-3561

       DIVISION OF
CORPORATION FINANCE

        March 18, 2008

Via Mail and Fax

Robert M. Knight, Jr.
Executive Vice President - Finance   and Chief Financial Officer
Union Pacific Corporation 1400 Douglas Street
Omaha, NE 68179

 RE:  Union Pacific Corporation
   Form 10-K for the Year Ended December 31, 2007
   File Number: 001-06075

Dear Mr. Knight:

 We have reviewed the above referenced filing and have the following comments.
We believe you should revise future filings in  response to some of the comments.  If you
disagree, we will consider your explanation as to why a revision is unnecessary.  Please be as detailed as necessary in your explan ation.  We also ask you to provide us with
information so we may better understand your  disclosure.  After reviewing this
information, we may raise additional comments.

 The purpose of our review process is to assist you in your compliance with the applicable disclosure requirements and to enhance the overall disclosure in your filings.
We look forward to working with you in thes e respects and welcome any questions.  Feel
free to call us at the telephone numbers  listed at the end of this letter.

 Please file your response to our comment s via EDGAR, under the label “corresp,”
within 10 business days from the date of this letter.

Union Pacific Corporation
March 18, 2008
Page 2 of 4
Form 10-K for the Year Ended December 31, 2007

Governmental and Environmental Regulation, page 6
Governmental Regulation, page 6

1. We note that you are subject to a variety of governmental regulation.  In connection
with this and in view of your substantial investment in properties, please tell us
whether there are any legal obl igations with respect to retirement of your properties
associated with such regulation and your consideration of FAS 143 and FIN 47 in this regard.

Management’s Discussion and Analysis …, page 20
Results of Operations, page 22
Operating Revenue, page 22

2. In regard to your fuel surcharge, please di sclose in your next Form 10-Q the expected
impact of (i) the limitations established by the STB, (ii) the new fuel surcharge program, and (iii) the resetti ng of the base fuel price on the amount of related revenue
recognized.

Consolidated Statements of Financial Position, page 49

3. Please disclose any individual amounts in “o ther current assets” and “other current
liabilities” in excess of 5% of total curre nt assets and total current liabilities,
respectively.  Refer to Rules 5-02.8 and .20 of Regulation S-X.

Consolidated Statements of Cash Flows, page 50

4. Please explain to us, with a view to di sclosing, the basis for presenting “proceeds
from completed equipment financings” as an  investing rather than as a financing
activity.

Notes to the Consolidated Financial Statements, page 52
Note 1. Significant Accounting Policies, page 52
Property and Depreciation, page 52

5. Please tell us and disclose the service life for each class of depreciable property.  In
connection with this, explain to us the correlation between (i) the applicable service
lives, (ii) the average age of the equipmen t, as disclosed on page 12, and (iii) the
quotient of accumulated depreciation divided by total costs of “properties.”  For example, accumulated depreciation is only 25%  of the total cost  of properties at
December 31, 2007, suggesting that the equi pment on page 12 has a substantial
remaining life despite the exis ting lengthy average age reported.

Union Pacific Corporation
March 18, 2008
Page 3 of 4
6. We note that you made capital investments totaling $3.1 billion in 2007.  Please (i)
quantify for us the significant components of these investments that are attributable to
“maintenance,” as you have referred to on pa ge 12,  (ii) explain to us why it is
appropriate to capitalize maintenance and provide us an underlying accounting
policy, (iii) explain to us with specificity how you differe ntiate between repairs and
maintenance that are expensed as incurred from maintenance that is capitalized, and (iv) tell us whether you capitalize any in ternal payroll costs as it relates to
maintenance.  As part of your response with regard to (iii), if you state that maintenance that appreciably extends the life, increases the capacity, or improves the efficiency or safety of an underlying asset,  please (i) explain with  specificity how you
measure the change and make these determinatio ns and (ii) provide us with examples.

7. If not included as part of your response to the preceding comment, please explain to us how you determine what constitutes (i) an “improve[ment]” of track infrastructure,
as discussed on page 33, and (ii) an “upgrad e” to your locomotive and freight car fleet
when it does not constitute a purchase of additional locomotives or freight cars, as also discussed on page 33.

We urge all persons who are responsible for the accuracy and adequacy of the
disclosure in the filings to be certain that the filings include all information required under the Securities Exchange Act of 1934 and that they have provided all information
investors require for an informed invest ment decision.  Since the company and its
management are in possession of all facts re lating to a company’s disclosure, they are
responsible for the accuracy and adequacy of the disclosures they have made.

In connection with responding to our comments, please provide, in writing, a
statement from the company acknowledging that:
‚ the company is responsible for the adequacy and accuracy of the disclosures in the filings;
‚ staff comments or changes to disclosure  in response to staff comments do not
foreclose the Commission from taking any action with respect to the filings; and
‚ the company may not assert staff comme nts as a defense in any proceeding
initiated by the Commission or any person under the federal secu rities laws of the
United States.

 In addition, please be advi sed that the Division of En forcement has access to all
information you provide to the staff of the Divi sion of Corporation Fi nance in our review
of your filings or in response to our comments on your filings.

Union Pacific Corporation
March 18, 2008
Page 4 of 4
You may contact Doug Jones at 202-551-3309 with any questions.  You may also
contact me at 202-551-3812.

 Sincerely,

 Michael Fay
 Branch Chief