RANGE RESTORATIO

ENDANGERED HUMPBA

AT THE PARIA RIVER M

Larry Stevens, 

Grand Canyon Wildlands Coun
OBJECTIVES

A. Initiate discussion of HBC reintroduction 

Paria R. confluence with TWG – ratio

B. Obtain feedback from TWG - concerns an

DISCUSSION TOPICS

1. Geography of the lower Paria River2. Ponding of the lower Paria River dur3. Historical presence of HBC in the Par4. Paria River flows and water quality 3. Research issues6. Design of experimental rearing ponds7. Funding, compliance, implementation
Old Paria 

New Paria R. Gauge

Lonely Dell Ranch

LF Grave

Paria River

GEOGR

THE LOWER 

Old Crossing

Mormon Dam

Paria R. Mouth
Gravel Pits

LF La

Ram

Flow

LF Road
TRIBUTARY MOUTH PON

DURING MAINSTREAM FL

1. Stage of mainstream serves as dam, pondin

to that elevation

2. Timing = May-July, depending on mainstre

a period with low likelihood of tributary h

3. Complex flows at mouth, but slowto stall4. Productivity likely increases as suspended 

out of ponded

water

5. Likely favorable conditions for rapid growt6. Pon

ding

process largely eliminated by G

C 

flood control

7. Effort here is to explore HBC range and ha

options through construction of small exp
50K

100K

150K

200K

Old Paria 

New Paria R. Gauge

Lonely Dell Ranch

LF Grave

Paria River
DOCUMENTATION OF 

IN THE LOWER PARIA RIV

1. Interviews with historical resident: Sp2. Discussion with Wendel

Minckley

3. AGFD reports4. Other evidence –

Other interviews, AG

U. Michigan collections?

Of all the changes known about HBC in the region, the reduction in range is the best docchange. Evidence indicates that the Paria

Ri

Lees Ferry area supported the second largesin the Grand Canyon region; however, that pbeen extirpated. 
PARIA RIVER FLOWS AN

1. Paria

River flows well studied (Graf, Toppi

Winter snowmelt from Bryce Canyon Summer monsoon floods, mid-late July High concentrations of fine sediments

2. Stage-related pond area survey needed3. Water quality

Some data availableFlow augmented by East Sevier transbWater temperature upstream from Lon

98

oF in mid-July, with low DO

SC and pH well within HBC tolerance 

Effort here is not to introduce a HBC into the 

but simply into experimental ponds at the 
Paria River Pond
VERY PRELIMINARY PON

20’

Shallows

Shallows

Deeper Area

with structure

Shallo

grave

To Paria

River

Gates

Pond Lining Footprint
RESEARCH TOPICS THAT MAY BE 

WITH SUITABLE EXPERIMENTA

FOR HBC OR OTHER NATIV

1. Turbidity and predation2. Competition with native and non-na

different life stages

3. Foodbase responses4. Thermal influences on growth5. In system propagation6. Dispersal behavior of stock7. Other research topics
ADVANTAGES OF PARIA M

EXPERIMENAL POND

1. Ready access2. Excellent research opportunity3. Inexpensive4. Expendable / replaceable if high flow5. Low maintenance6. Relatively easy compliance7. Inconspicuous (minimal impact on vi8. Eventually restore HBC to Paria

mou

HBC were formerly abundant

NEED TO DETERMINE: Sequence of actio

Number of pondDesign specifics
NEXT STEPS

Integrate project into HBC planConduct a feasibility study, including com

background information

Develop pond and experimental design wit

collaborators

Secure funding with participating organizConduct compliance (NPS, FWS, AGFD, SDevelop and implement outreach programConduct pilot program on FMS for one yeUndertake first year of HBC workEvaluate, proceed, improve as indicated