For many years, WLWC/WCMH-TV has shared NBC programming in the eastern part of the market with WHIZ-TV (channel 18) in Zanesville despite channel 4 itself covering Zanesville and covering weather reports as far east as Cambridge (part of the Wheeling, West Virginia/Steubenville, Ohio market and served by WTOV-TV for NBC) and all other major network affiliates in Columbus covering Muskingum County as default affiliates, since Zanesville is considered a separate TV market from Columbus. WHIZ-TV would also serve somewhat as a buffer for WCMH-TV after WTAE-TV in Pittsburgh signed on in 1958 and had to "box in" its signal to protect then-WLWC and three other stations also broadcasting on channel 4.