Supplemental road log 1: From intersection of Piedra Lumbre road and NM-197 to Star Lake and Pueblo Alto Trading Posts
— Edward C. Beaumont and Gretchen K. Hoffman

This trip begins at mileage 91. 9 of the First-Day Road Log and continues west into the San Juan Basin. We will stay on NM-197 for the majority of the trip and will be on well-maintained dirt roads for the remainder of the journey. The route begins at the southeastern edge of the Star Lake coal field, on a sagebrush plain underlain by Lewis Shale. The highway heads southwest toward Trujillo Canyon and Torreon Wash, where the intertonguing rel ationships of the Lewis Shale-Cliff House Sandstone- Menefee Formation are well exposed. From the Torreon Wash bridge to the Torreon Trading Post, there are several "clinkered " shale and coal outcrops of the upper Menefee coalbearing sequence along the route. This nonmarine. transgressive sequence was deposited shoreward of, and intertongues with, the barrier sandstones of La Yentana Tongue of the Cliff House Sandstone. Most of the coals in the Torreon area are thin , 2 to 3 ft thick, but southeast in the La Yentana coal field some upper Menefee coals attain a thickness of 9 ft.

West of the Torreon Trading Post the route ascends the Menefee-Cliff House-Lewis sequence through a canyon paralleling Vicente Arroyo . Outcrops in the canyon illustrate the intertonguing re lationship between the Cliff House Sandstone and the Lewis Shale . The crest of the mesa is capped by a massive sandstone of the Cliff House Sandstone and an overlook 0 .6 mi beyond the crest provides a panoramic view of the southeastern San Juan Basin . Continuing west on NM-197 the highway parallels the dip slope, 3- 5° north-northwest, and we traverse the Lewis ShaleCliff House Sandstone sequence for approximately 8 mi. To the south the skyline is dominated by Chaco Mesa, a predominant topographic feature in northeastern McKinley County. Chaco Mesa is capped by the Cliff House Sandstone and trends N60°W, parallel to the strandline of the Late Cretaceous sea in this region. The highway turns to the northwest and slowly ascends the section. Here the Lewis Shale is overlain by the regressive barrier sandstones of the Pictured Cliffs. Because of the similari ty in depositional environments, the outcrops of the Pictured Cliffs sandstones along the highway are difficult to distinguish from those of the older Cliff House.

Turning north on the Star Lake compressor plant road, we enter an area known for its oil, gas and coal potential. The small oil fie ld to the west of the road is called the Star Mesaverde and produces from sandstones in the lower Menefee Formation. Coal and "clinkered" shale outcrops in the vicinity are in the Fruitland Formation. The site of the old Star Lake Trading Post is near the center of the Star Lake coal field, defined by the Fruitland Formation outcrop from southeast of the town of Cuba to 6 mi west of Pueblo Pintado Trading Post, 11 mi to the northwest. Drilling by the New Mexico Bureau of Mines and Mineral Resources indicates the Fruitland Formation is on average 2 17 ft thick in the Star Lake fi eld . The typical coal section contains seven economical seams (~2.5 ft) that average 6.5 ft, with coals up to 20 ft thick.

The road log continues north and northwest from Star Lake Trading Post on the Gas Company of New Mexico 's pipeline road . Near the Gas Company's compressor station is the transitional contact between the Fruitland and overlying Kirtland Formation. Northwest of the station the dark gray to black shale outcrops are in the Kirtland Formation, distinguished from the Fruitland by the lack of significant coals and, particularly noticeable in outcrop, by the lack of sandstones. The shale- and silt-dominated Kirtland sequence weathers to the badlands topography we see for several miles along the route until turning southwest on the road to Pueblo Alto, NM-93. The road traverses the Fruitland for about I mi, although outcrops are obscured by eolian sand. The route continues past Tanner Lake and on to the old Pueblo Alto Trading Post. Near the crest of the hill south of the trading post is the contact between the Pictured Cliffs and the Fruitland Formation. The dirt road intersects with NM-197 and the route continues east, back toward the intersection with the Star Lake plant road, where the log ends.