I have just left the consulting firm Enterprise Knowledge, LLC, to pursue independent taxonomy consulting as Hedden Information Management.
What was sort of my position (although not as senior) as a Taxonomy Consultant at Enterprise Knowledge (HQ in Arlington, VA) is open. It requests at least 2 years of taxonomy experience. It can be remote in any U.S. state (except California, Alaska, or Hawaii). https://enterprise-knowledge.com/careers/current-openings/#op-640021-taxonomy-consultant
Occasionally they have ontologist positions, too, but not now.