Wyo. Stat. § 7-17-103: Minimum requirements.

(a) For the purpose of warning and protecting the traveling public, the following minimum requirements shall be met by peace officers establishing temporary roadblocks if time and circumstances allow:

(i) The temporary roadblock shall be established at a point on the highway clearly visible at a distance of not less than two hundred (200) yards in either direction;

(ii) At the point of the temporary roadblock flashing warning lights shall be visible to oncoming traffic for a distance of not less than two hundred (200) yards. The display of flashing emergency warning lights on a marked law enforcement vehicle shall be sufficient under this paragraph; and

(iii) At least one (1) person working a temporary roadblock shall be in uniform and visible and at least one (1) vehicle used in a temporary roadblock shall be clearly marked as a law enforcement vehicle.