William E. “Bill” Tanis



William E. “Bill” Tanis



Bill Tanis has been a partner of Ireland Stapleton Pryor & Pascoe, P.C., one of the leading general practice law firms in Denver, Colorado, since 1982. Mr. Tanis has extensive experience in general corporate and securities law matters, including initial public offerings, private placements, partnerships, joint ventures, acquisitions and dispositions, and entity formations. He has provided general advice to, and completed transactions for, public and private clients in industries as diverse as real estate, construction, equipment leasing, medical devices, banking, financial services, oil and gas, and renewable energy. Mr. Tanis’ experience also includes counseling and representing companies that have been financed by venture capital firms as well as companies that have been acquired by private equity firms. His client roster includes several non-profit corporations. During his career, Mr. Tanis has worked closely with boards of directors and management on strategic planning, financial matters, employee incentive plans, corporate governance issues and restructurings. Mr. Tanis is a past member of the Arapahoe County Ethics Committee and the Willows Water District Board.


  • Colorado Bar Association
  • Colorado Bar Association Ethics Committee
  • American Law Institute
  • Monte Pascoe Civic Leadership Award Committee Member
  • Board Member, Willows Water District

Contact Info

Practice Areas


  • Harvard Law School J.D., 1975
  • London School of Economics M.S. Economics 1972
  • Dartmouth College B.A., 1971

Honors & Awards

  • Recognized by The Best Lawyers in America® for Business Organization and Corporate Law
  • 2018 Recipient of the YMCA of Metropolitan Denver’s Volunteer of the Year Award


  • Admitted to practice in Colorado