MESA LABORATORIES INC /CO/ — Director's Dealing 2013

May 6, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MESA LABORATORIES INC /CO (MLAB)
CIK: 0000724004
Period of Report: 2013-05-03

Reporting Person: CAMPBELL H STUART (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-05-03	Common Stock	M	250	$29.2	Acquired	76098	Direct
2013-05-03	Common Stock	M	500	$25.56	Acquired	76598	Direct
2013-05-03	Common Stock	M	600	$16.6	Acquired	77198	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-05-03	Non-Qualified Stock Option	$29.2	X	250	Disposed	2021-04-06	Common Stock (250)	Direct
2013-05-03	Non-Qualified Stock Option	$25.56	X	500	Disposed	2020-04-01	Common Stock (500)	Direct
2013-05-03	Non-Qualified Stock Option	$16.6	X	600	Disposed	2019-04-01	Common Stock (600)	Direct

Footnotes

F1: 25% of Grant Exercisable on each of the first 4 anniversary dates following 04/06/2011

F2: 25% of Grant Exercisable on each of 4 anniversary dates following 04/01/2010

F3: 25% of Grant Exercisable on each of the first 4 anniversary dates following 04/01/2009