A short history of Kanawha Glass Company summarized from Popular 50s & 60s Glass, Color Along the River by Leslie Pina:
When Dunbar Glass Co. in Dunbar WV closed in 1953 some of the former workers joined together to form Kanawha Glass Specialities Co., named after the nearby Kanawha River. In 1957, they changed the name to Kanawha Glass Company. By 1960 they began production of colorful decorative glass including crackle glass (for which they are most noted).
In 1969 Kanawha purchased Hamon Handcrafted Glass in Scott Depot, WV. Hamon crackle glass maintained its identity under Kanawha. Hamon made hand mould blown glass and Kanawha made pressed glass.
In the early 1970s Kanawha began making cased milk glass. My own comment: It is often mistaken for Fenton glass hence my interest in Kanawha.
Production continued until 1987 when Kanawha was sold to Raymond Dereume Glass Inc. in Punxsutawey, PA. The glassworks closed in 1989.
So from all that you piece, if it is Kanawha, dates from 1960 to 1989. My guess would be from the 1960s when they were making the most colored pressed glass.