Larry Stevens–River Map and Guide

Larry Stevens–River Map and Guide

Larry Stevens recently released his updated guide to The Colorado River in the Grand Canyon. The guide is in full color and includes a map of the river similar to the Belknap River Guide. River miles in the book correspond to the most recent USGS-GCMRC measurements. Rapid ratings are based in order of four water levels: Very Low(1,000-3,000 cfs), Low (3,000-9,000 cfs), Medium (9,000-16,000 cfs) and High (16,000-35,000 cfs). The guide also includes camps that are commonly used and a sun and shade diagram that lets boaters know about when the shade will hit in the afternoon, and when the sunlight will hit the camp in the morning.


In addition to the river map the book is full of useful information about Geography, Geology, Human History, Biology, and Ecology. Larry Stevens has a PhD in Zoology, and is a natural historian and river runner with 35 years engaged in ecological research in the American Southwest.


The Geography Section of the book engages the reader by introducing the Colorado Plateau region and explaining Spatial Scale. A graph showing the average daily temperature and mean monthly precipitation is also included in this section. The section finishes up with some bleak predictions for the Colorado River because of Climate Change.


The Geology Section of the guide is very in depth and will keep the novice and seasoned geologist intrigued with its great diagrams and in depth information. The geology section includes a diagram of geologic stratigraphy of the Grand Canyon, Landscape evolution paleographic illustrations by Ron Blakey, and a River Basin Development diagram.


The human history timeline of the Grand Canyon is another highlight of the book. This timeline starts with the Paleoindian Period and ends at present day. Find when Georgie White first experienced the river and when Verlen Kruger did the first non-motorized up run through the Grand Canyon.


The Biology and Ecology section has a lot of great information and pictures of the flora and fauna of the area. It is especially interesting to see photos of all of the native fish of the Colorado River and read about the challenges they face.


Colorado River & Trail Expeditions just got a new shipment of these books. To order this new guidebook for the Grand Canyon and the Colorado River just visit the new Colorado River & Trail Expeditions Store.

More About the Larry Stevens–River Map and Guide

Sandy beach inside a cavern overlooks a river, with red rock canyon walls and a blue sky.
February 15, 2026
The Colorado River below Glen Canyon Dam flows through the lower reaches of Glen Canyon on its way to Lees Ferry , forming one of the most studied and discussed stretches of river in the American Southwest. Released from the base of the dam, the water is typically clear and tightly controlled. In recent years, however, lower water levels in Lake Powell have caused releases to come from shallower depths, warming the river compared to past decades and changing the conditions downstream. This reach is calm and approachable, making it a popular destination for kayaking, rafting, fishing, and flatwater exploration. Visitors often take time to linger along the banks, explore side canyons, and pull over at small beaches and alcoves—experiencing the river at an unhurried pace that encourages observation and learning.  Quick facts about this stretch of river naturally help frame why it matters:
Glen Canyon Dam with bridge and canyon walls under a blue sky. Water flows towards the dam.
February 12, 2026
The Dirty Devil River joins the Colorado River at River Mile 169.5. John Wesley Powell camped at this confluence on July 28, 1869, describing the tributary as extremely muddy and foul-smelling. Jack Sumner later named it the Dirty Devil. The Dirty Devil is formed by the confluence of Muddy Creek and the Fremont River near present-day Hanksville, Utah. The Fremont River originates at Fish Lake and flows along the Waterpocket Fold through Capitol Reef National Park. Muddy Creek drains the San Rafael Swell. Historic Context — Powell’s Expeditions: Powell’s 1869 expedition recorded the Dirty Devil as both a geographic reference and a warning. In his later expeditions of 1871–72, Powell returned with improved boats and a scientific mandate. Tributaries such as the Dirty Devil became fixed reference points for mapping and geologic observation. Powell’s journals note the heavy silt load and poor water quality here, and his party avoided using the Dirty Devil as a water source when possible.
Camping gear on a sandy beach near a red rock wall and river under a cloudy sky.
February 12, 2026
Camping and Dining