I searched the web, but couldn't find any official Mohave County info.

The Kingman landfill hours as of 11/17/17:

Mon - Fri:  7 am - 3 pm
Sat: 8 am - 3 pm

From http://legacy.azdeq.gov/enviro.....ctive.html

Mohave County

Arizona Strip Community Landfill
Owner: Towns of Colorado City & Fredonia
Operator: Arizona Strip Landfill Corp. - 928-875-2646
Location: Hwy 389, 9 miles southeast of Colorado City

Cerbat Municipal Solid Waste Landfill
Owner: County of Mohave
Operator: Gambi Disposal, Inc. - 928-565-2777
7300 Mineral Park Rd., Golden Valley
Location: 12 miles north of Kingman on Mineral Park Rd., east of Hwy 93

Lake Havasu City Landfill
Owner: BLM and Lake Havasu City
Operator: Allied Waste Industries - 928-855-441
3251 E. Chenoweth Dr, Lake Havasu City
Location: 5 miles north of Lake Havasu City and 2.5 miles east of SR 95

Mohave Valley Landfill
Owner: Mohave County
Operator: Mesa Disposal, Inc. - 928-758-0000
3999 East El Rodeo Rd., Fort Mohave
Location: 6 miles northeast of the intersection of Hwy 95 and El Rodeo Rd.