Digging for steps here goes through more than one office. The City of South Lake Tahoe names TRPA as the authority on land coverage in the Tahoe basin, and TRPA does the site assessments and coverage checks. Under TRPA's Qualified Exempt process, you get other approvals, such as a building permit, before work begins.
Whether your steps need a permit from the city isn't something I guess at. I ask the city, work out which office it goes through and help you file it before we start. The season matters too. TRPA's Qualified Exempt path only covers digging, filling or backfilling from May 1 to October 15, with other conditions, including a volume that doesn't go over 7 cubic yards.
Industry guidance also urges caution about pouring outdoor concrete in late fall, winter or early spring if it might freeze while it's still soaked. So steps are a spring and summer job here, and I'll tell you to wait for a better week rather than pour into bad conditions. We're based in South Lake Tahoe and do the same work in the cities around it.