miry

According to the historian Edward Hasted, writing in the 1770s, Cooling was “an unfrequented place, the roads of which are deep and miry, and it is as unhealthy as it is unpleasant.”

From New York Times ● Nov. 6, 2018

Without access to the inter-stage area, which turns the miry walk between the two main stages into a comparatively short hop, the following would not be possible.

From Time ● Jul. 7, 2014

It took two hours to cross the miry plain, though it was but a mile and a half wide.

From Stanley's Adventures in the Wilds of Africa A Graphic Account of the Several Expeditions of Henry M. Stanley into the Heart of the Dark Continent by Joel Tyler Headley

As a clownish Fellow was driving his cart along a deep miry lane, the wheels stuck so fast in the clay, that the horses could not draw them out.

From ?sop's Fables, Embellished with One Hundred and Eleven Emblematical Devices. by ?sop

“God grant that I may be drawing near some inhabited place,” said I.  The path now grew very miry, and there were pools of water on either side. 

From Wild Wales The People, Laguage & Scenery by George Henry Borrow