Our Communities

Serving in SoCal, by Land and Sea

Our employees in Southern California have a passion for their community – and it shows in the projects we deliver and the people we serve.

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Serving in SoCal, by Land and Sea
Pioneers

H.H. Henningson - From Cowboy to Community-Minded Engineer

Our founder blended a brilliant mind with a drive to help communities and clients.

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H.H. Henningson - From Cowboy to Community-Minded Engineer
Anniversary Video

One Hundred and HDR

A century of pushing the boundaries of what's possible. A legacy of bringing innovative solutions to every project – no matter the challenge. A future of collaborating and creating the only way we know how. Together.

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One Hundred and HDR
Pieces of Our Past

Early Journal Also Withstands Test of Time

A field book has survived the test of time. For the last 98 years, it's gone from employee to employee, passed down from mentor to protégé. Its origins lead straight to the hands of company founder H.H. Henningson.

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Early Journal Also Withstands Test of Time

Our History at a Glance

1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
2020
Henningson Engineering Company is born

Henningson Engineering Company is born

Henningson brings power to the plains

Henningson brings power to the plains

July 21, 1917

The firm quickly earns a reputation for Work Well Done

The firm quickly earns a reputation for Work Well Done

August 5, 1917

Henningson Engineering continues to grow

Henningson Engineering continues to grow

Municipal engineering increases

Municipal engineering increases

1920 - 1929

Rural Electrification Distinguishes Firm

Rural Electrification Distinguishes Firm

Henningson Engineering Branches Out

Henningson Engineering Branches Out

A new era of leadership

A new era of leadership

HDR poised for growth

HDR poised for growth

HDR Attains Worldwide Reach

HDR Attains Worldwide Reach

HDR Builds on International Profile

HDR Builds on International Profile

HDR Thrives as Employee-Owned Firm

HDR Thrives as Employee-Owned Firm

One Company, Many Solutions

One Company, Many Solutions

Growing Number of Worldwide Projects Leads to Expansion

Growing Number of Worldwide Projects Leads to Expansion

HDR celebrates its 100th Year Anniversary

HDR celebrates its 100th Year Anniversary

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