1 EXHIBIT 99.1 PRELIMINARY COPY -- SUBJECT TO COMPLETION PROXY BARRETT RESOURCES CORPORATION PROXY SOLICITED BY THE BARRETT RESOURCES BOARD OF DIRECTORS FOR THE SPECIAL MEETING OF STOCKHOLDERS TO BE HELD ON AUGUST 2, 2001 The undersigned hereby appoints Eugene A. Lang, Jr. and Stephen J. Malcolm, and each of them, as attorneys and proxies of the undersigned, with full power of substitution, to vote all of the shares of common stock of Barrett Resources Corporation, a Delaware corporation, which the undersigned may be entitled to vote at the special meeting of stockholders of Barrett Resources Corporation scheduled for Thursday, August 2, 2001, at the Westin Hotel-Tabor Center, 1672 Lawrence Street, Denver, Colorado, at 9:00 a.m. Denver time, and at any and all postponements, continuations and adjournments thereof, with all powers that the undersigned would possess if personally present, upon and in respect of the following matters and in accordance with the following instructions. UNLESS A CONTRARY DIRECTION IS INDICATED, THIS PROXY WILL BE VOTED FOR PROPOSAL 1 AS MORE SPECIFICALLY DESCRIBED IN THE PROXY STATEMENT/PROSPECTUS. IF SPECIFIC INSTRUCTIONS ARE INDICATED, THIS PROXY WILL BE VOTED IN ACCORDANCE THEREWITH. (Continued, and to be dated and signed on other side) 2 This proxy when properly executed will be voted Please mark your vote as [X] in the manner directed herein by the undersigned indicated in this example. stockholder. IF NO DIRECTION IS GIVEN, THIS PROXY WILL BE VOTED FOR APPROVAL OF THE AGREEMENT AND PLAN OF MERGER LISTED IN PROPOSAL 1. YOUR BOARD OF DIRECTORS RECOMMENDS A VOTE FOR PROPOSAL 1 PROPOSAL 1: To approve and adopt the Agreement and Plan of Merger, dated as of May 7, 2001, among The Williams Companies, Inc., Resources Acquisition Corp., a wholly owned subsidiary of Williams, and Barrett Resources Corporation. [ ] FOR [ ] AGAINST [ ] ABSTAIN IN THEIR DISCRETION, THE PROXIES ARE AUTHORIZED TO CONSIDER Please sign exactly as your name appears AND ACT UPON SUCH OTHER MATTERS OR PROPOSALS AS MAY hereon. If the shares are registered in PROPERLY BE BROUGHT BEFORE THE SPECIAL MEETING AND ANY the names of two or more persons, each POSTPONEMENT, CONTINUATION AND ADJOURNMENT THEREOF. should sign. Executors, administrators, trustees, guardians and attorneys-in-fact should add their titles. If signer is a corporation, please give full corporate name and have a duly authorized officer sign, stating title. If signer is a partnership, please sign in partnership name by authorized person. PLEASE VOTE, SIGN, DATE AND PROMPTLY RETURN THIS PROXY IN THE ENCLOSED RETURN ENVELOPE WHICH IS POSTAGE PREPAID IF MAILED IN THE UNITED STATES. SIGNATURE:------------------------ DATE:------------ SIGNATURE:------------------------ DATE:------------