Kinder Morgan (NYSE:KMI) is one of America's best high-yield dividend growth stocks, but recently some readers have expressed concern about how long its exceptional track record of dividend growth can realistically last, given that at some point America's shale energy boom must come to an end. Let's examine three reasons Kinder's dividend growth dominance is likely to continue for decades, perhaps even after America's shale revolution peaks. 

How long can backlog growth last?
The first step in determining Kinder's dividend growth prospects for the long term -- specifically, 10-plus years -- is to look at its total backlog of growth projects, which is fueled by America's current shale energy boom. 

The current backlog stands at $18.3 billion, with approximately another $19.2 billion in its "shadow backlog" -- projects that management thinks make attractive investments but that it hasn't yet obtained sufficient long-term commitments for. 

Thus, Kinder's total backlog is around $37.5 billion, which represents approximately 10 years' worth of growth at current capital expenditure investment levels. 

Fortunately for investors, Kinder's backlog is likely to remain extremely large, if not grow much bigger in coming years, because of the enormous potential of America's shale oil and gas resources.

The U.S. energy boom is a multi-generational affair

Source: EIA Annual Energy Outlook 2015 report.

There are two takeaways from these charts from the U.S. Energy Information Energy: U.S. oil production isn't likely to peak until at least 2019, and U.S. natural gas production is likely to continue growing until at least 2040, which is as far out as the government's projections go.

However, notice how much the projections have changed between 2015 (the blue line) and 2013 (the purple line). Two years ago, the EIA projected that U.S. oil production would peak in 2016, and now that prediction has been pushed back to 2019, thanks to new innovations the oil industry has developed.

Thus, it's quite possible that not only will U.S. gas production growth continue well past 2040, but also, thanks to technological innovation, U.S. oil production might not peak until much later than currently believed. The EIA projects that total proven oil reserves in the contiguous 48 states will increase 43% between 2012 and 2040, while proven dry gas reserves are expected to grow 26% in that same time period.

Thanks to projections such as these, the Interstate Natural Gas Association of America's latest midstream infrastructure report estimates that $641 billion will need to be invested between 2014 and 2035 to support increasing gas and oil production. 

Source: INGAA Foundation.

With Kinder's already enormous total backlog representing just 5.9% of the expected new midstream infrastructure over the next two decades, investors probably don't need to worry for a long time yet about a lack of growth prospects to keep the backlog fed and expanding. 

Post-backlog growth option No. 1: mergers and acquisitions 
But what about when America's limited -- if enormous -- resources do cause oil and gas production to finally peak? While that scenario would finally curtail Kinder's backlog growth prospects, management has two main options to keep the dividend growth humming along for many more years.

First, there's the ability to grow through mergers and acquisitions, which both allow Kinder to keep increasing its distributable cash flow, which funds the dividend. Currently there are over 120 MLPs with a combined market cap of over $875 million, figures that are growing steadily over time, from which Kinder can go acquisition-hunting.

With a total of over $1.5 trillion in combined new infrastructure needs plus potential acquisitions, Kinder probably has several decades of strong growth ahead of it, but the benefit of acquisitions isn't in just acquiring assets. There are substantial tax benefits as well. For example, Kinder's $71 billion buyout of its three MLPs is expected to result in $55 billion in tax deferments over the next 14 years. 

In other words, Kinder might be able to reap massive tax deferments from acquiring assets that are older and whose depreciation value can be reset. Not only would that help it grow its dividend at a projected 10% per year through 2020, but it would also lower its cost of capital and improve its overall profitability. 

Post-backlog growth option No. 2: share buybacks
Once Kinder's growth options are exhausted, whether through infrastructure investments or acquisitions, its enormous pool of long-term contracted assets will generate enormous free cash flow, which can be used to reduce its share count and grow free cash flow per share.

Kinder's 2014 growth capital spending was $3.6 billion. When growth spending doesn't exist, that money becomes free cash flow -- in a no-growth scenario, 2014 FCF would have more than tripled to $5.3 billion -- and with a decreasing share count, dividends per share can keep growing strongly for a long time.

Takeaway: Kinder Morgan is likely to remain a dividend growth champion for decades to come
While it's true that America's shale energy bonanza can't continue indefinitely, it's likely to roll on for several more decades. Even after that time ends, though, Kinder has options for continuing to grow its dividend for many more years.