.ca.us domains list

What is .ca.us TLD

.ca.us is a geographic second‑level designation within the .us country‑code top‑level domain, reserved for California’s public-sector sphere. In practice, .ca.us domains generally appear as third‑level names (for example, city.ca.us) that map municipalities, school districts, libraries, and special districts to the DNS. When we profile .ca.us domains and .ca.us websites, we see a strong focus on resident services, compliance notices, and operational information. Governance and eligibility are delegated, so registration policies and technical baselines vary by locality. From an intelligence perspective, this namespace signals jurisdiction and continuity, but presents heterogeneous SSL, DNSSEC, and uptime characteristics influenced by decentralized management. These patterns matter for discovery, benchmarking, and risk assessments across California’s civic web. Explore .ca.us domain datasets from webatla.

History and key features of .ca.us TLD

Historically, .ca.us formed part of the United States’ locality hierarchy under .us, created to mirror civic geography in the early commercial internet. .ca.us domains followed patterns such as cityname.ca.us and k12.ca.us, supporting municipalities and K‑12 education networks. Today, most .ca.us websites remain tied to public administration, with eligibility and naming conventions generally aligned to government and school structures. Key features include geographic signaling, hierarchical labeling, and delegated administration, alongside uneven modernization: DNSSEC and TLS adoption vary by operator, and legacy mail or subnets often persist. We observe gradual consolidation toward .gov or .edu for some institutions, but a substantial installed base endures for continuity and records. Start exploring .ca.us domain datasets from webatla.

Why and who choose the .ca.us domain

Organizations choose .ca.us for clear geographic identity, regulatory alignment, and continuity with established systems. Typical registrants include counties, cities, public safety agencies, school districts, libraries, utilities, and transit authorities operating long‑lived infrastructure. For .ca.us domains and .ca.us websites, the benefits are consistent naming within California’s civic framework and discoverability for residents seeking official information. The trade‑offs are heterogeneous standards, variable certificate management, and occasional reliance on legacy platforms, which we quantify through uptime, DNS, and content signals. Private companies rarely adopt the namespace; public institutions with durable mandates tend to retain it, especially when migration costs or records obligations are material. Explore detailed .ca.us domain datasets from webatla.