Utah Const. art. VI, § 17 – [Impeachment by House.]

(1) The House of Representatives shall have the sole power of impeachment, but in order to impeach, two-thirds of all the members elected must vote therefor.
(2) If not already convened in an annual general session, the House of Representatives may convene for the purpose of impeachment if a poll of members conducted by the Speaker of the House indicates that two-thirds of the members of the House of Representatives are in favor of convening.