Based on coworkers in the Engineering/transportation/environmental consultant firm I work with and our government clients
Mid-level managers (over 20-40 people): government workers just crack 100k (likely 15+ years of experience, most 20+), while those in private sector earn another 20-40k and can get there faster if they're good/no major setbacks in their career.
Engineers (civil, structural, environmental groups): can get to 100k fairly quickly, say 5-7 years, if they're good/clients like them, and especially if they take on project management tasks.
Other professions (eg urban planners, software developers): those that make 100k mostly have 10+ years of experience and/or take on project management or sales/client service roles.
Very few of the government workers I interact with are close to 100k. Only those that are office managers (oversee 30+) or have one of the few high up engineering or IT positions. There are many licensed engineers and experienced software developers making 50-60k.
Note: this is from a mid-sized (~250k) city, that is affordable.