Section 23177 Of Article 3. Settlement Of Boundary Disputes From California Government Code >> Division 1. >> Title 3. >> Chapter 2. >> Article 3.

. Every common boundary between counties which has been mutually used by the counties adjacent thereto for the purpose of the assessment and collection of taxes for a period of 15 years continuously prior to the effective date of this section is hereby confirmed, validated, and declared to be legally established.