Capitol Reef's Natural Resources: Good Night Skies, Fair Air, and Gaps to Fill

Capitol Reef National Park has some of the darkest night skies in the country, and the Park Service has now rated them: good. Its air quality came out fair, and its soundscape, water and fish are a mix of fair ratings and gaps. A 2022 Natural Resource Condition Assessment (NRCA) looked at eleven resources at the park, in southcentral Utah, and this article covers six of them.

A view in Capitol Reef National Park overlooking the Waterpocket Fold, a geologic feature that formed between 50 and 70 million years ago (NPS photo).

What an NRCA does

The National Park Service uses NRCAs to give an efficient, scientifically defensible update on the current condition of a limited number of important natural resources, and to identify critical data gaps and the drivers and stressors that affect them, such as climate change, invasive species, disease, human disturbance and air pollution. Of the eleven resources here, five got a condition assessment, a thorough evaluation of current condition, and six got a gap analysis, which shows what is and is not known and suggests how to collect what is missing.

The park covers about 381 square miles, nearly all managed as wilderness. It has the Waterpocket Fold, the longest exposed monocline in North America, and one of the largest concentrations of rare and endemic plants among national park units. The Fremont River and other perennial streams, plus springs, seeps and tinajas, are vital water sources in the high desert, and at least 58 mammals have been confirmed there. The eleven resources are night sky and air quality, soundscape, springs, seeps and tinajas, streams, pinyon-juniper woodlands, grasslands and shrublands, rare plants, songbirds, Mexican spotted owl, desert bighorn sheep and fish. This article covers night sky and air quality, soundscape, springs, seeps and tinajas, streams, pinyon-juniper woodlands and fish.

Night sky and air quality

The night sky, including the Milky Way, at Capitol Reef (NPS/Phil Sisto).

The assessment used four indicators for the night sky and two (daytime visibility and ozone) for air quality. The night sky is in good condition and air quality is fair. In 2018 the visual range was 86 to 179 miles; without pollution it would be 127 to 197 miles. Air quality, and so visibility, will probably improve, because the largest coal-fired power plant in the western U.S., south of the park, was decommissioned in 2019.

Soundscape

A model from the NPS Natural Sounds and Night Skies Division predicts the effect of noise. It indicates fair conditions park-wide and in the primitive and semi-primitive management zones, which cover 93% of the park, and poor conditions in the remaining zones, including the road corridor. The corridor is only 0.2% of the park but can have a large effect on soundscape quality. Staff were also recording continuous audio at three locations, which will tell more about natural sounds and noise sources once it is analyzed.

Springs, seeps, tinajas and streams

Perennial streams are few, and springs, seeps and tinajas (pools of water in rock) are scattered, so wildlife such as desert bighorn sheep, mule deer, birds and amphibians depend on them. Tinajas even hold invertebrates adapted to the short life cycle that temporary pools demand. The assessment found there could be as many as 170 springs and seeps. More than 50 macroinvertebrate species have been recorded in the park's tinajas, including two species of fairy shrimp, pond snails and many insects. Tinajas had been only partly mapped, but a Park Service geology database shows that 35% of the park could support them.

A tinaja in Capitol Reef (NPS/Ann Huston).

Pinyon-juniper woodlands

These woodlands, built on pinyon pine and juniper, are the main vegetation over most of the park. They give wildlife habitat and plant cover that protects watersheds. In parts of the West they have become dense or are spreading into other vegetation, so the assessment checked. It rated tree density, age-class distribution and songbirds as good, and the increase in crown cover as good/fair. Less than 3.5% of the park has relatively dense woodland, the densest along the western border in the far north and center, and there is little sign of a move toward closed woodland with more fire risk. Most of the woodland is open and early in development, and likely to stay so for some time. It still supports two songbirds that depend on it, the pinyon jay and the ash-throated flycatcher.

Pinyon-juniper woodland at Capitol Reef (NPS/Shauna Cotrell).

Fish

At least three native and eight non-native fish species are known in the perennial streams, and the roundtail chub, another native, used to be there. The park holds only a small part of the streams that pass through it, so upstream activity affects water quality and quantity. Climate change and a waterfall barrier on the Fremont River, created when Utah Highway 24 was built, also matter, since a barrier or lack of flow stops fish moving up and down stream.

The Fremont River, the primary perennial stream in Capitol Reef (NPS/Ann Huston).

The fish community in the Fremont River is in fair condition: most native species were consistently present, but non-native fish were recorded too. Habitat for native fish is good/fair in the Fremont and unknown in the other streams. Dissolved oxygen and temperature were good/fair in the Fremont and other streams, with temperatures sometimes elevated. Contaminants were rated fair/poor: seven contaminants of emerging concern were found in the Fremont and three in Sulphur Creek, while most of those searched for were not found.

What the park can do

A manager-scientist discussion links findings to action. The assessment's lessons:

• Several stressors affect each resource, which makes protecting them hard.
• Warmer temperatures and more frequent, more intense droughts affect the water or vegetation of the resources studied.
• Partnering with other agencies would help inform adjacent developments about landscape-level effects on dark night skies and soundscape, and manage the natural processes of pinyon-juniper woodlands across boundaries, since national forest woodlands lie west of the park.
• For songbirds and the Mexican spotted owl, the project suggested actions such as alternative ways to monitor or examine current data.
• For water, three action areas emerged: a springs and groundwater study, integrating riparian and springs monitoring with other federal agencies at the watershed level, and monitoring streamflow, connectivity and fish recruitment.

Sources

• National Park Service, Condition of Selected Natural Resources at Capitol Reef: 2022 Assessment, summarizing Struthers K and others, Natural resource conditions at Capitol Reef National Park: Findings & management considerations for selected resources, Natural Resource Report NPS/NCPN/NRR—2022/2406, National Park Service, 2022; rewritten in hubnx's own words.