The manufacturing index for the Fed's 10th District, which includes Kansas, Oklahoma, Colorado, Wyoming, Nebraska and parts of Missouri and New Mexico, slipped from minus four in October to minus six in November.
The two-month negative streak is the first time since mid-2009 that the index has been in the red for two consecutive months.
Manufacturing slowed at durable goods-producing factories, but rose slightly in non-durable goods production plants. Durable goods are intended to last at least three years.
Overall, the region's production index was unchanged at minus six, while the indexes for new orders fell for the third straight month to the lowest level in three years, the Fed said in a statement.
Numbers in the index below zero indicate an activity is contracting.
The component index measuring employment rose to the break-even point, climbing from minus six to zero in November.