Rapid City, SD Sign Regulations: Freeway-Facing Signs (2026)
Key Facts
- Standard billboard cap
- 250 sq ft per face, 30 ft
- I-90 freeway sign cap
- 672 sq ft, 40 ft height
- I-90 distance trigger
- Within 100 ft of I-90 ROW
- Spacing rule
- 1,000 ft minimum between billboards
- Governing section
- § 17.50.090B.4
Summary
Off-premises signs in Rapid City are capped at 250 square feet per face and 30 feet in height, but a sign within 100 feet of the Interstate 90 right-of-way that advertises to I-90 traffic can grow to 672 square feet and 40 feet under § 17.50.090B.4.
B. Size, height and spacing regulations for off-premises signage. Off-premises signs shall be constructed in accordance with the following regulations: ... ... 2. Off-premises signs shall have no more than 2 faces. Each face of an off-premises sign may have a maximum area of 250 square feet, except as provided in subsection B.4. ... ... 3. The maximum height of an off-premises sign is 30 feet, except as provided in subsection B.4. ... ... 4. For off-premises signs which are located within 100 feet of the right of way for Interstate 90 and which advertise to traffic on Interstate 90, an off-premises sign may have a maximum area of 672 square feet and may have a maximum height of 40 feet.
Full Breakdown
3. 4 carves out a specific, larger allowance for freeway-facing billboards: a sign located within 100 feet of the Interstate 90 right-of-way that advertises to traffic on I-90 may reach 672 square feet of face area and 40 feet in height, well above the citywide baseline. 090B's spacing rules, including the requirement that new off-premises signs sit at least 1,000 feet from any other off-premises sign (measured radially from each sign's base) and at least 50 feet from any on-premises sign, and it cannot be located nearer than 1,500 feet from the nearest off-premises sign as measured along the road it's intended to be viewed from. 3. 4.
Violations & Fines
An off-premises sign built beyond the 672-square-foot, 40-foot allowance for I-90-facing signs, or a standard billboard exceeding the citywide 250-square-foot, 30-foot cap, violates § 17.50.090B and can be declared an unlawful sign under § 17.50.080C, subject to removal at the owner's expense and the general penalty in § 1.12.010.
Frequently Asked Questions
How big can a billboard be along Interstate 90 in Rapid City?
Why does Rapid City allow bigger signs near I-90?
Do freeway-facing billboards in Rapid City still have to meet spacing rules?
Sources & Official References
Other rules in Rapid City
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